// SPDX-License-Identifier: GPL-2.0+
/*
 * Driver for the PLX NET2280 USB device controller.
 * Specs and errata are available from <http://www.plxtech.com>.
 *
 * PLX Technology Inc. (formerly NetChip Technology) supported the
 * development of this driver.
 *
 *
 * CODE STATUS HIGHLIGHTS
 *
 * This driver should work well with most "gadget" drivers, including
 * the Mass Storage, Serial, and Ethernet/RNDIS gadget drivers
 * as well as Gadget Zero and Gadgetfs.
 *
 * DMA is enabled by default.
 *
 * MSI is enabled by default.  The legacy IRQ is used if MSI couldn't
 * be enabled.
 *
 * Note that almost all the errata workarounds here are only needed for
 * rev1 chips.  Rev1a silicon (0110) fixes almost all of them.
 */

/*
 * Copyright (C) 2003 David Brownell
 * Copyright (C) 2003-2005 PLX Technology, Inc.
 * Copyright (C) 2014 Ricardo Ribalda - Qtechnology/AS
 *
 * Modified Seth Levy 2005 PLX Technology, Inc. to provide compatibility
 *      with 2282 chip
 *
 * Modified Ricardo Ribalda Qtechnology AS  to provide compatibility
 *      with usb 338x chip. Based on PLX driver
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/prefetch.h>
#include <linux/io.h>

#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/unaligned.h>

#define DRIVER_DESC             "PLX NET228x/USB338x USB Peripheral Controller"
#define DRIVER_VERSION          "2005 Sept 27/v3.0"

#define EP_DONTUSE              13      /* nonzero */

#define USE_RDK_LEDS            /* GPIO pins control three LEDs */


static const char driver_name[] = "net2280";
static const char driver_desc[] = DRIVER_DESC;

static const u32 ep_bit[9] = { 0, 17, 2, 19, 4, 1, 18, 3, 20 };
static const char ep0name[] = "ep0";

#define EP_INFO(_name, _caps) \
        { \
                .name = _name, \
                .caps = _caps, \
        }

static const struct {
        const char *name;
        const struct usb_ep_caps caps;
} ep_info_dft[] = { /* Default endpoint configuration */
        EP_INFO(ep0name,
                USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_ALL)),
        EP_INFO("ep-a",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
        EP_INFO("ep-b",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
        EP_INFO("ep-c",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
        EP_INFO("ep-d",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
        EP_INFO("ep-e",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
        EP_INFO("ep-f",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
        EP_INFO("ep-g",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
        EP_INFO("ep-h",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
}, ep_info_adv[] = { /* Endpoints for usb3380 advance mode */
        EP_INFO(ep0name,
                USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_ALL)),
        EP_INFO("ep1in",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep2out",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep3in",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep4out",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep1out",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep2in",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep3out",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep4in",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
};

#undef EP_INFO

/* mode 0 == ep-{a,b,c,d} 1K fifo each
 * mode 1 == ep-{a,b} 2K fifo each, ep-{c,d} unavailable
 * mode 2 == ep-a 2K fifo, ep-{b,c} 1K each, ep-d unavailable
 */
static ushort fifo_mode;

/* "modprobe net2280 fifo_mode=1" etc */
module_param(fifo_mode, ushort, 0644);

/* enable_suspend -- When enabled, the driver will respond to
 * USB suspend requests by powering down the NET2280.  Otherwise,
 * USB suspend requests will be ignored.  This is acceptable for
 * self-powered devices
 */
static bool enable_suspend;

/* "modprobe net2280 enable_suspend=1" etc */
module_param(enable_suspend, bool, 0444);

#define DIR_STRING(bAddress) (((bAddress) & USB_DIR_IN) ? "in" : "out")

static char *type_string(u8 bmAttributes)
{
        switch ((bmAttributes) & USB_ENDPOINT_XFERTYPE_MASK) {
        case USB_ENDPOINT_XFER_BULK:    return "bulk";
        case USB_ENDPOINT_XFER_ISOC:    return "iso";
        case USB_ENDPOINT_XFER_INT:     return "intr";
        }
        return "control";
}

#include "net2280.h"

#define valid_bit       cpu_to_le32(BIT(VALID_BIT))
#define dma_done_ie     cpu_to_le32(BIT(DMA_DONE_INTERRUPT_ENABLE))

static void ep_clear_seqnum(struct net2280_ep *ep);
static void stop_activity(struct net2280 *dev,
                                        struct usb_gadget_driver *driver);
static void ep0_start(struct net2280 *dev);

/*-------------------------------------------------------------------------*/
static inline void enable_pciirqenb(struct net2280_ep *ep)
{
        u32 tmp = readl(&ep->dev->regs->pciirqenb0);

        if (ep->dev->quirks & PLX_LEGACY)
                tmp |= BIT(ep->num);
        else
                tmp |= BIT(ep_bit[ep->num]);
        writel(tmp, &ep->dev->regs->pciirqenb0);

        return;
}

static int
net2280_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
{
        struct net2280          *dev;
        struct net2280_ep       *ep;
        u32                     max;
        u32 tmp = 0;
        u32 type;
        unsigned long           flags;
        static const u32 ep_key[9] = { 1, 0, 1, 0, 1, 1, 0, 1, 0 };
        int ret = 0;

        ep = container_of(_ep, struct net2280_ep, ep);
        if (!_ep || !desc || ep->desc || _ep->name == ep0name ||
                        desc->bDescriptorType != USB_DT_ENDPOINT) {
                pr_err("%s: failed at line=%d\n", __func__, __LINE__);
                return -EINVAL;
        }
        dev = ep->dev;
        if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {
                ret = -ESHUTDOWN;
                goto print_err;
        }

        /* erratum 0119 workaround ties up an endpoint number */
        if ((desc->bEndpointAddress & 0x0f) == EP_DONTUSE) {
                ret = -EDOM;
                goto print_err;
        }

        if (dev->quirks & PLX_PCIE) {
                if ((desc->bEndpointAddress & 0x0f) >= 0x0c) {
                        ret = -EDOM;
                        goto print_err;
                }
                ep->is_in = !!usb_endpoint_dir_in(desc);
                if (dev->enhanced_mode && ep->is_in && ep_key[ep->num]) {
                        ret = -EINVAL;
                        goto print_err;
                }
        }

        /* sanity check ep-e/ep-f since their fifos are small */
        max = usb_endpoint_maxp(desc);
        if (ep->num > 4 && max > 64 && (dev->quirks & PLX_LEGACY)) {
                ret = -ERANGE;
                goto print_err;
        }

        spin_lock_irqsave(&dev->lock, flags);
        _ep->maxpacket = max;
        ep->desc = desc;

        /* ep_reset() has already been called */
        ep->stopped = 0;
        ep->wedged = 0;
        ep->out_overflow = 0;

        /* set speed-dependent max packet; may kick in high bandwidth */
        set_max_speed(ep, max);

        /* set type, direction, address; reset fifo counters */
        writel(BIT(FIFO_FLUSH), &ep->regs->ep_stat);

        if ((dev->quirks & PLX_PCIE) && dev->enhanced_mode) {
                tmp = readl(&ep->cfg->ep_cfg);
                /* If USB ep number doesn't match hardware ep number */
                if ((tmp & 0xf) != usb_endpoint_num(desc)) {
                        ret = -EINVAL;
                        spin_unlock_irqrestore(&dev->lock, flags);
                        goto print_err;
                }
                if (ep->is_in)
                        tmp &= ~USB3380_EP_CFG_MASK_IN;
                else
                        tmp &= ~USB3380_EP_CFG_MASK_OUT;
        }
        type = (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
        if (type == USB_ENDPOINT_XFER_INT) {
                /* erratum 0105 workaround prevents hs NYET */
                if (dev->chiprev == 0100 &&
                                dev->gadget.speed == USB_SPEED_HIGH &&
                                !(desc->bEndpointAddress & USB_DIR_IN))
                        writel(BIT(CLEAR_NAK_OUT_PACKETS_MODE),
                                &ep->regs->ep_rsp);
        } else if (type == USB_ENDPOINT_XFER_BULK) {
                /* catch some particularly blatant driver bugs */
                if ((dev->gadget.speed == USB_SPEED_SUPER && max != 1024) ||
                    (dev->gadget.speed == USB_SPEED_HIGH && max != 512) ||
                    (dev->gadget.speed == USB_SPEED_FULL && max > 64)) {
                        spin_unlock_irqrestore(&dev->lock, flags);
                        ret = -ERANGE;
                        goto print_err;
                }
        }
        ep->is_iso = (type == USB_ENDPOINT_XFER_ISOC);
        /* Enable this endpoint */
        if (dev->quirks & PLX_LEGACY) {
                tmp |= type << ENDPOINT_TYPE;
                tmp |= desc->bEndpointAddress;
                /* default full fifo lines */
                tmp |= (4 << ENDPOINT_BYTE_COUNT);
                tmp |= BIT(ENDPOINT_ENABLE);
                ep->is_in = (tmp & USB_DIR_IN) != 0;
        } else {
                /* In Legacy mode, only OUT endpoints are used */
                if (dev->enhanced_mode && ep->is_in) {
                        tmp |= type << IN_ENDPOINT_TYPE;
                        tmp |= BIT(IN_ENDPOINT_ENABLE);
                } else {
                        tmp |= type << OUT_ENDPOINT_TYPE;
                        tmp |= BIT(OUT_ENDPOINT_ENABLE);
                        tmp |= (ep->is_in << ENDPOINT_DIRECTION);
                }

                tmp |= (4 << ENDPOINT_BYTE_COUNT);
                if (!dev->enhanced_mode)
                        tmp |= usb_endpoint_num(desc);
                tmp |= (ep->ep.maxburst << MAX_BURST_SIZE);
        }

        /* Make sure all the registers are written before ep_rsp*/
        wmb();

        /* for OUT transfers, block the rx fifo until a read is posted */
        if (!ep->is_in)
                writel(BIT(SET_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
        else if (!(dev->quirks & PLX_2280)) {
                /* Added for 2282, Don't use nak packets on an in endpoint,
                 * this was ignored on 2280
                 */
                writel(BIT(CLEAR_NAK_OUT_PACKETS) |
                        BIT(CLEAR_NAK_OUT_PACKETS_MODE), &ep->regs->ep_rsp);
        }

        if (dev->quirks & PLX_PCIE)
                ep_clear_seqnum(ep);
        writel(tmp, &ep->cfg->ep_cfg);

        /* enable irqs */
        if (!ep->dma) {                         /* pio, per-packet */
                enable_pciirqenb(ep);

                tmp = BIT(DATA_PACKET_RECEIVED_INTERRUPT_ENABLE) |
                        BIT(DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE);
                if (dev->quirks & PLX_2280)
                        tmp |= readl(&ep->regs->ep_irqenb);
                writel(tmp, &ep->regs->ep_irqenb);
        } else {                                /* dma, per-request */
                tmp = BIT((8 + ep->num));       /* completion */
                tmp |= readl(&dev->regs->pciirqenb1);
                writel(tmp, &dev->regs->pciirqenb1);

                /* for short OUT transfers, dma completions can't
                 * advance the queue; do it pio-style, by hand.
                 * NOTE erratum 0112 workaround #2
                 */
                if ((desc->bEndpointAddress & USB_DIR_IN) == 0) {
                        tmp = BIT(SHORT_PACKET_TRANSFERRED_INTERRUPT_ENABLE);
                        writel(tmp, &ep->regs->ep_irqenb);

                        enable_pciirqenb(ep);
                }
        }

        tmp = desc->bEndpointAddress;
        ep_dbg(dev, "enabled %s (ep%d%s-%s) %s max %04x\n",
                _ep->name, tmp & 0x0f, DIR_STRING(tmp),
                type_string(desc->bmAttributes),
                ep->dma ? "dma" : "pio", max);

        /* pci writes may still be posted */
        spin_unlock_irqrestore(&dev->lock, flags);
        return ret;

print_err:
        dev_err(&ep->dev->pdev->dev, "%s: error=%d\n", __func__, ret);
        return ret;
}

static int handshake(u32 __iomem *ptr, u32 mask, u32 done, int usec)
{
        u32     result;

        do {
                result = readl(ptr);
                if (result == ~(u32)0)          /* "device unplugged" */
                        return -ENODEV;
                result &= mask;
                if (result == done)
                        return 0;
                udelay(1);
                usec--;
        } while (usec > 0);
        return -ETIMEDOUT;
}

static const struct usb_ep_ops net2280_ep_ops;

static void ep_reset_228x(struct net2280_regs __iomem *regs,
                          struct net2280_ep *ep)
{
        u32             tmp;

        ep->desc = NULL;
        INIT_LIST_HEAD(&ep->queue);

        usb_ep_set_maxpacket_limit(&ep->ep, ~0);
        ep->ep.ops = &net2280_ep_ops;

        /* disable the dma, irqs, endpoint... */
        if (ep->dma) {
                writel(0, &ep->dma->dmactl);
                writel(BIT(DMA_SCATTER_GATHER_DONE_INTERRUPT) |
                        BIT(DMA_TRANSACTION_DONE_INTERRUPT) |
                        BIT(DMA_ABORT),
                        &ep->dma->dmastat);

                tmp = readl(&regs->pciirqenb0);
                tmp &= ~BIT(ep->num);
                writel(tmp, &regs->pciirqenb0);
        } else {
                tmp = readl(&regs->pciirqenb1);
                tmp &= ~BIT((8 + ep->num));     /* completion */
                writel(tmp, &regs->pciirqenb1);
        }
        writel(0, &ep->regs->ep_irqenb);

        /* init to our chosen defaults, notably so that we NAK OUT
         * packets until the driver queues a read (+note erratum 0112)
         */
        if (!ep->is_in || (ep->dev->quirks & PLX_2280)) {
                tmp = BIT(SET_NAK_OUT_PACKETS_MODE) |
                BIT(SET_NAK_OUT_PACKETS) |
                BIT(CLEAR_EP_HIDE_STATUS_PHASE) |
                BIT(CLEAR_INTERRUPT_MODE);
        } else {
                /* added for 2282 */
                tmp = BIT(CLEAR_NAK_OUT_PACKETS_MODE) |
                BIT(CLEAR_NAK_OUT_PACKETS) |
                BIT(CLEAR_EP_HIDE_STATUS_PHASE) |
                BIT(CLEAR_INTERRUPT_MODE);
        }

        if (ep->num != 0) {
                tmp |= BIT(CLEAR_ENDPOINT_TOGGLE) |
                        BIT(CLEAR_ENDPOINT_HALT);
        }
        writel(tmp, &ep->regs->ep_rsp);

        /* scrub most status bits, and flush any fifo state */
        if (ep->dev->quirks & PLX_2280)
                tmp = BIT(FIFO_OVERFLOW) |
                        BIT(FIFO_UNDERFLOW);
        else
                tmp = 0;

        writel(tmp | BIT(TIMEOUT) |
                BIT(USB_STALL_SENT) |
                BIT(USB_IN_NAK_SENT) |
                BIT(USB_IN_ACK_RCVD) |
                BIT(USB_OUT_PING_NAK_SENT) |
                BIT(USB_OUT_ACK_SENT) |
                BIT(FIFO_FLUSH) |
                BIT(SHORT_PACKET_OUT_DONE_INTERRUPT) |
                BIT(SHORT_PACKET_TRANSFERRED_INTERRUPT) |
                BIT(DATA_PACKET_RECEIVED_INTERRUPT) |
                BIT(DATA_PACKET_TRANSMITTED_INTERRUPT) |
                BIT(DATA_OUT_PING_TOKEN_INTERRUPT) |
                BIT(DATA_IN_TOKEN_INTERRUPT),
                &ep->regs->ep_stat);

        /* fifo size is handled separately */
}

static void ep_reset_338x(struct net2280_regs __iomem *regs,
                                        struct net2280_ep *ep)
{
        u32 tmp, dmastat;

        ep->desc = NULL;
        INIT_LIST_HEAD(&ep->queue);

        usb_ep_set_maxpacket_limit(&ep->ep, ~0);
        ep->ep.ops = &net2280_ep_ops;

        /* disable the dma, irqs, endpoint... */
        if (ep->dma) {
                writel(0, &ep->dma->dmactl);
                writel(BIT(DMA_ABORT_DONE_INTERRUPT) |
                       BIT(DMA_PAUSE_DONE_INTERRUPT) |
                       BIT(DMA_SCATTER_GATHER_DONE_INTERRUPT) |
                       BIT(DMA_TRANSACTION_DONE_INTERRUPT),
                       /* | BIT(DMA_ABORT), */
                       &ep->dma->dmastat);

                dmastat = readl(&ep->dma->dmastat);
                if (dmastat == 0x5002) {
                        ep_warn(ep->dev, "The dmastat return = %x!!\n",
                               dmastat);
                        writel(0x5a, &ep->dma->dmastat);
                }

                tmp = readl(&regs->pciirqenb0);
                tmp &= ~BIT(ep_bit[ep->num]);
                writel(tmp, &regs->pciirqenb0);
        } else {
                if (ep->num < 5) {
                        tmp = readl(&regs->pciirqenb1);
                        tmp &= ~BIT((8 + ep->num));     /* completion */
                        writel(tmp, &regs->pciirqenb1);
                }
        }
        writel(0, &ep->regs->ep_irqenb);

        writel(BIT(SHORT_PACKET_OUT_DONE_INTERRUPT) |
               BIT(SHORT_PACKET_TRANSFERRED_INTERRUPT) |
               BIT(FIFO_OVERFLOW) |
               BIT(DATA_PACKET_RECEIVED_INTERRUPT) |
               BIT(DATA_PACKET_TRANSMITTED_INTERRUPT) |
               BIT(DATA_OUT_PING_TOKEN_INTERRUPT) |
               BIT(DATA_IN_TOKEN_INTERRUPT), &ep->regs->ep_stat);

        tmp = readl(&ep->cfg->ep_cfg);
        if (ep->is_in)
                tmp &= ~USB3380_EP_CFG_MASK_IN;
        else
                tmp &= ~USB3380_EP_CFG_MASK_OUT;
        writel(tmp, &ep->cfg->ep_cfg);
}

static void nuke(struct net2280_ep *);

static int net2280_disable(struct usb_ep *_ep)
{
        struct net2280_ep       *ep;
        unsigned long           flags;

        ep = container_of(_ep, struct net2280_ep, ep);
        if (!_ep || !ep->desc || _ep->name == ep0name) {
                pr_err("%s: Invalid ep=%p or ep->desc\n", __func__, _ep);
                return -EINVAL;
        }
        spin_lock_irqsave(&ep->dev->lock, flags);
        nuke(ep);

        if (ep->dev->quirks & PLX_PCIE)
                ep_reset_338x(ep->dev->regs, ep);
        else
                ep_reset_228x(ep->dev->regs, ep);

        ep_vdbg(ep->dev, "disabled %s %s\n",
                        ep->dma ? "dma" : "pio", _ep->name);

        /* synch memory views with the device */
        (void)readl(&ep->cfg->ep_cfg);

        if (!ep->dma && ep->num >= 1 && ep->num <= 4)
                ep->dma = &ep->dev->dma[ep->num - 1];

        spin_unlock_irqrestore(&ep->dev->lock, flags);
        return 0;
}

/*-------------------------------------------------------------------------*/

static struct usb_request
*net2280_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
{
        struct net2280_ep       *ep;
        struct net2280_request  *req;

        if (!_ep) {
                pr_err("%s: Invalid ep\n", __func__);
                return NULL;
        }
        ep = container_of(_ep, struct net2280_ep, ep);

        req = kzalloc(sizeof(*req), gfp_flags);
        if (!req)
                return NULL;

        INIT_LIST_HEAD(&req->queue);

        /* this dma descriptor may be swapped with the previous dummy */
        if (ep->dma) {
                struct net2280_dma      *td;

                td = dma_pool_alloc(ep->dev->requests, gfp_flags,
                                &req->td_dma);
                if (!td) {
                        kfree(req);
                        return NULL;
                }
                td->dmacount = 0;       /* not VALID */
                td->dmadesc = td->dmaaddr;
                req->td = td;
        }
        return &req->req;
}

static void net2280_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
        struct net2280_ep       *ep;
        struct net2280_request  *req;

        ep = container_of(_ep, struct net2280_ep, ep);
        if (!_ep || !_req) {
                dev_err(&ep->dev->pdev->dev, "%s: Invalid ep=%p or req=%p\n",
                                                        __func__, _ep, _req);
                return;
        }

        req = container_of(_req, struct net2280_request, req);
        WARN_ON(!list_empty(&req->queue));
        if (req->td)
                dma_pool_free(ep->dev->requests, req->td, req->td_dma);
        kfree(req);
}

/*-------------------------------------------------------------------------*/

/* load a packet into the fifo we use for usb IN transfers.
 * works for all endpoints.
 *
 * NOTE: pio with ep-a..ep-d could stuff multiple packets into the fifo
 * at a time, but this code is simpler because it knows it only writes
 * one packet.  ep-a..ep-d should use dma instead.
 */
static void write_fifo(struct net2280_ep *ep, struct usb_request *req)
{
        struct net2280_ep_regs  __iomem *regs = ep->regs;
        u8                      *buf;
        u32                     tmp;
        unsigned                count, total;

        /* INVARIANT:  fifo is currently empty. (testable) */

        if (req) {
                buf = req->buf + req->actual;
                prefetch(buf);
                total = req->length - req->actual;
        } else {
                total = 0;
                buf = NULL;
        }

        /* write just one packet at a time */
        count = ep->ep.maxpacket;
        if (count > total)      /* min() cannot be used on a bitfield */
                count = total;

        ep_vdbg(ep->dev, "write %s fifo (IN) %d bytes%s req %p\n",
                        ep->ep.name, count,
                        (count != ep->ep.maxpacket) ? " (short)" : "",
                        req);
        while (count >= 4) {
                /* NOTE be careful if you try to align these. fifo lines
                 * should normally be full (4 bytes) and successive partial
                 * lines are ok only in certain cases.
                 */
                tmp = get_unaligned((u32 *)buf);
                cpu_to_le32s(&tmp);
                writel(tmp, &regs->ep_data);
                buf += 4;
                count -= 4;
        }

        /* last fifo entry is "short" unless we wrote a full packet.
         * also explicitly validate last word in (periodic) transfers
         * when maxpacket is not a multiple of 4 bytes.
         */
        if (count || total < ep->ep.maxpacket) {
                tmp = count ? get_unaligned((u32 *)buf) : count;
                cpu_to_le32s(&tmp);
                set_fifo_bytecount(ep, count & 0x03);
                writel(tmp, &regs->ep_data);
        }

        /* pci writes may still be posted */
}

/* work around erratum 0106: PCI and USB race over the OUT fifo.
 * caller guarantees chiprev 0100, out endpoint is NAKing, and
 * there's no real data in the fifo.
 *
 * NOTE:  also used in cases where that erratum doesn't apply:
 * where the host wrote "too much" data to us.
 */
static void out_flush(struct net2280_ep *ep)
{
        u32     __iomem *statp;
        u32     tmp;

        statp = &ep->regs->ep_stat;

        tmp = readl(statp);
        if (tmp & BIT(NAK_OUT_PACKETS)) {
                ep_dbg(ep->dev, "%s %s %08x !NAK\n",
                        ep->ep.name, __func__, tmp);
                writel(BIT(SET_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
        }

        writel(BIT(DATA_OUT_PING_TOKEN_INTERRUPT) |
                BIT(DATA_PACKET_RECEIVED_INTERRUPT),
                statp);
        writel(BIT(FIFO_FLUSH), statp);
        /* Make sure that stap is written */
        mb();
        tmp = readl(statp);
        if (tmp & BIT(DATA_OUT_PING_TOKEN_INTERRUPT) &&
                        /* high speed did bulk NYET; fifo isn't filling */
                        ep->dev->gadget.speed == USB_SPEED_FULL) {
                unsigned        usec;

                usec = 50;              /* 64 byte bulk/interrupt */
                handshake(statp, BIT(USB_OUT_PING_NAK_SENT),
                                BIT(USB_OUT_PING_NAK_SENT), usec);
                /* NAK done; now CLEAR_NAK_OUT_PACKETS is safe */
        }
}

/* unload packet(s) from the fifo we use for usb OUT transfers.
 * returns true iff the request completed, because of short packet
 * or the request buffer having filled with full packets.
 *
 * for ep-a..ep-d this will read multiple packets out when they
 * have been accepted.
 */
static int read_fifo(struct net2280_ep *ep, struct net2280_request *req)
{
        struct net2280_ep_regs  __iomem *regs = ep->regs;
        u8                      *buf = req->req.buf + req->req.actual;
        unsigned                count, tmp, is_short;
        unsigned                cleanup = 0, prevent = 0;

        /* erratum 0106 ... packets coming in during fifo reads might
         * be incompletely rejected.  not all cases have workarounds.
         */
        if (ep->dev->chiprev == 0x0100 &&
                        ep->dev->gadget.speed == USB_SPEED_FULL) {
                udelay(1);
                tmp = readl(&ep->regs->ep_stat);
                if ((tmp & BIT(NAK_OUT_PACKETS)))
                        cleanup = 1;
                else if ((tmp & BIT(FIFO_FULL))) {
                        start_out_naking(ep);
                        prevent = 1;
                }
                /* else: hope we don't see the problem */
        }

        /* never overflow the rx buffer. the fifo reads packets until
         * it sees a short one; we might not be ready for them all.
         */
        prefetchw(buf);
        count = readl(&regs->ep_avail);
        if (unlikely(count == 0)) {
                udelay(1);
                tmp = readl(&ep->regs->ep_stat);
                count = readl(&regs->ep_avail);
                /* handled that data already? */
                if (count == 0 && (tmp & BIT(NAK_OUT_PACKETS)) == 0)
                        return 0;
        }

        tmp = req->req.length - req->req.actual;
        if (count > tmp) {
                /* as with DMA, data overflow gets flushed */
                if ((tmp % ep->ep.maxpacket) != 0) {
                        ep_err(ep->dev,
                                "%s out fifo %d bytes, expected %d\n",
                                ep->ep.name, count, tmp);
                        req->req.status = -EOVERFLOW;
                        cleanup = 1;
                        /* NAK_OUT_PACKETS will be set, so flushing is safe;
                         * the next read will start with the next packet
                         */
                } /* else it's a ZLP, no worries */
                count = tmp;
        }
        req->req.actual += count;

        is_short = (count == 0) || ((count % ep->ep.maxpacket) != 0);

        ep_vdbg(ep->dev, "read %s fifo (OUT) %d bytes%s%s%s req %p %d/%d\n",
                        ep->ep.name, count, is_short ? " (short)" : "",
                        cleanup ? " flush" : "", prevent ? " nak" : "",
                        req, req->req.actual, req->req.length);

        while (count >= 4) {
                tmp = readl(&regs->ep_data);
                cpu_to_le32s(&tmp);
                put_unaligned(tmp, (u32 *)buf);
                buf += 4;
                count -= 4;
        }
        if (count) {
                tmp = readl(&regs->ep_data);
                /* LE conversion is implicit here: */
                do {
                        *buf++ = (u8) tmp;
                        tmp >>= 8;
                } while (--count);
        }
        if (cleanup)
                out_flush(ep);
        if (prevent) {
                writel(BIT(CLEAR_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
                (void) readl(&ep->regs->ep_rsp);
        }

        return is_short || ((req->req.actual == req->req.length) &&
                        !req->req.zero);
}

/* fill out dma descriptor to match a given request */
static void fill_dma_desc(struct net2280_ep *ep,
                                        struct net2280_request *req, int valid)
{
        struct net2280_dma      *td = req->td;
        u32                     dmacount = req->req.length;

        /* don't let DMA continue after a short OUT packet,
         * so overruns can't affect the next transfer.
         * in case of overruns on max-size packets, we can't
         * stop the fifo from filling but we can flush it.
         */
        if (ep->is_in)
                dmacount |= BIT(DMA_DIRECTION);
        if ((!ep->is_in && (dmacount % ep->ep.maxpacket) != 0) ||
                                        !(ep->dev->quirks & PLX_2280))
                dmacount |= BIT(END_OF_CHAIN);

        req->valid = valid;
        if (valid)
                dmacount |= BIT(VALID_BIT);
        dmacount |= BIT(DMA_DONE_INTERRUPT_ENABLE);

        /* td->dmadesc = previously set by caller */
        td->dmaaddr = cpu_to_le32 (req->req.dma);

        /* 2280 may be polling VALID_BIT through ep->dma->dmadesc */
        wmb();
        td->dmacount = cpu_to_le32(dmacount);
}

static const u32 dmactl_default =
                BIT(DMA_SCATTER_GATHER_DONE_INTERRUPT) |
                BIT(DMA_CLEAR_COUNT_ENABLE) |
                /* erratum 0116 workaround part 1 (use POLLING) */
                (POLL_100_USEC << DESCRIPTOR_POLLING_RATE) |
                BIT(DMA_VALID_BIT_POLLING_ENABLE) |
                BIT(DMA_VALID_BIT_ENABLE) |
                BIT(DMA_SCATTER_GATHER_ENABLE) |
                /* erratum 0116 workaround part 2 (no AUTOSTART) */
                BIT(DMA_ENABLE);

static inline void spin_stop_dma(struct net2280_dma_regs __iomem *dma)
{
        handshake(&dma->dmactl, BIT(DMA_ENABLE), 0, 50);
}

static inline void stop_dma(struct net2280_dma_regs __iomem *dma)
{
        writel(readl(&dma->dmactl) & ~BIT(DMA_ENABLE), &dma->dmactl);
        spin_stop_dma(dma);
}

static void start_queue(struct net2280_ep *ep, u32 dmactl, u32 td_dma)
{
        struct net2280_dma_regs __iomem *dma = ep->dma;
        unsigned int tmp = BIT(VALID_BIT) | (ep->is_in << DMA_DIRECTION);

        if (!(ep->dev->quirks & PLX_2280))
                tmp |= BIT(END_OF_CHAIN);

        writel(tmp, &dma->dmacount);
        writel(readl(&dma->dmastat), &dma->dmastat);

        writel(td_dma, &dma->dmadesc);
        if (ep->dev->quirks & PLX_PCIE)
                dmactl |= BIT(DMA_REQUEST_OUTSTANDING);
        writel(dmactl, &dma->dmactl);

        /* erratum 0116 workaround part 3:  pci arbiter away from net2280 */
        (void) readl(&ep->dev->pci->pcimstctl);

        writel(BIT(DMA_START), &dma->dmastat);

        if (!ep->is_in)
                stop_out_naking(ep);
}

static void start_dma(struct net2280_ep *ep, struct net2280_request *req)
{
        u32                     tmp;
        struct net2280_dma_regs __iomem *dma = ep->dma;

        /* FIXME can't use DMA for ZLPs */

        /* on this path we "know" there's no dma active (yet) */
        WARN_ON(readl(&dma->dmactl) & BIT(DMA_ENABLE));
        writel(0, &ep->dma->dmactl);

        /* previous OUT packet might have been short */
        if (!ep->is_in && (readl(&ep->regs->ep_stat) &
                                BIT(NAK_OUT_PACKETS))) {
                writel(BIT(SHORT_PACKET_TRANSFERRED_INTERRUPT),
                        &ep->regs->ep_stat);

                tmp = readl(&ep->regs->ep_avail);
                if (tmp) {
                        writel(readl(&dma->dmastat), &dma->dmastat);

                        /* transfer all/some fifo data */
                        writel(req->req.dma, &dma->dmaaddr);
                        tmp = min(tmp, req->req.length);

                        /* dma irq, faking scatterlist status */
                        req->td->dmacount = cpu_to_le32(req->req.length - tmp);
                        writel(BIT(DMA_DONE_INTERRUPT_ENABLE) | tmp,
                                        &dma->dmacount);
                        req->td->dmadesc = 0;
                        req->valid = 1;

                        writel(BIT(DMA_ENABLE), &dma->dmactl);
                        writel(BIT(DMA_START), &dma->dmastat);
                        return;
                }
        }

        tmp = dmactl_default;

        /* force packet boundaries between dma requests, but prevent the
         * controller from automagically writing a last "short" packet
         * (zero length) unless the driver explicitly said to do that.
         */
        if (ep->is_in) {
                if (likely((req->req.length % ep->ep.maxpacket) ||
                                                        req->req.zero)){
                        tmp |= BIT(DMA_FIFO_VALIDATE);
                        ep->in_fifo_validate = 1;
                } else
                        ep->in_fifo_validate = 0;
        }

        /* init req->td, pointing to the current dummy */
        req->td->dmadesc = cpu_to_le32 (ep->td_dma);
        fill_dma_desc(ep, req, 1);

        req->td->dmacount |= cpu_to_le32(BIT(END_OF_CHAIN));

        start_queue(ep, tmp, req->td_dma);
}

static inline void
queue_dma(struct net2280_ep *ep, struct net2280_request *req, int valid)
{
        struct net2280_dma      *end;
        dma_addr_t              tmp;

        /* swap new dummy for old, link; fill and maybe activate */
        end = ep->dummy;
        ep->dummy = req->td;
        req->td = end;

        tmp = ep->td_dma;
        ep->td_dma = req->td_dma;
        req->td_dma = tmp;

        end->dmadesc = cpu_to_le32 (ep->td_dma);

        fill_dma_desc(ep, req, valid);
}

static void
done(struct net2280_ep *ep, struct net2280_request *req, int status)
{
        struct net2280          *dev;
        unsigned                stopped = ep->stopped;

        list_del_init(&req->queue);

        if (req->req.status == -EINPROGRESS)
                req->req.status = status;
        else
                status = req->req.status;

        dev = ep->dev;
        if (ep->dma)
                usb_gadget_unmap_request(&dev->gadget, &req->req, ep->is_in);

        if (status && status != -ESHUTDOWN)
                ep_vdbg(dev, "complete %s req %p stat %d len %u/%u\n",
                        ep->ep.name, &req->req, status,
                        req->req.actual, req->req.length);

        /* don't modify queue heads during completion callback */
        ep->stopped = 1;
        spin_unlock(&dev->lock);
        usb_gadget_giveback_request(&ep->ep, &req->req);
        spin_lock(&dev->lock);
        ep->stopped = stopped;
}

/*-------------------------------------------------------------------------*/

static int
net2280_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
        struct net2280_request  *req;
        struct net2280_ep       *ep;
        struct net2280          *dev;
        unsigned long           flags;
        int ret = 0;

        /* we always require a cpu-view buffer, so that we can
         * always use pio (as fallback or whatever).
         */
        ep = container_of(_ep, struct net2280_ep, ep);

        if (!_ep || (!ep->desc && ep->num != 0)) {
                pr_err("%s: Invalid ep=%p or ep->desc\n", __func__, _ep);
                return -EINVAL;
        }
        req = container_of(_req, struct net2280_request, req);
        if (!_req || !_req->complete || !_req->buf ||
                                !list_empty(&req->queue)) {
                ret = -EINVAL;
                goto print_err;
        }
        if (_req->length > (~0 & DMA_BYTE_COUNT_MASK)) {
                ret = -EDOM;
                goto print_err;
        }
        dev = ep->dev;
        if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {
                ret = -ESHUTDOWN;
                goto print_err;
        }

        /* FIXME implement PIO fallback for ZLPs with DMA */
        if (ep->dma && _req->length == 0) {
                ret = -EOPNOTSUPP;
                goto print_err;
        }

        /* set up dma mapping in case the caller didn't */
        if (ep->dma) {
                ret = usb_gadget_map_request(&dev->gadget, _req,
                                ep->is_in);
                if (ret)
                        goto print_err;
        }

        ep_vdbg(dev, "%s queue req %p, len %d buf %p\n",
                        _ep->name, _req, _req->length, _req->buf);

        spin_lock_irqsave(&dev->lock, flags);

        _req->status = -EINPROGRESS;
        _req->actual = 0;

        /* kickstart this i/o queue? */
        if  (list_empty(&ep->queue) && !ep->stopped &&
                !((dev->quirks & PLX_PCIE) && ep->dma &&
                  (readl(&ep->regs->ep_rsp) & BIT(CLEAR_ENDPOINT_HALT)))) {

                /* use DMA if the endpoint supports it, else pio */
                if (ep->dma)
                        start_dma(ep, req);
                else {
                        /* maybe there's no control data, just status ack */
                        if (ep->num == 0 && _req->length == 0) {
                                allow_status(ep);
                                done(ep, req, 0);
                                ep_vdbg(dev, "%s status ack\n", ep->ep.name);
                                goto done;
                        }

                        /* PIO ... stuff the fifo, or unblock it.  */
                        if (ep->is_in)
                                write_fifo(ep, _req);
                        else if (list_empty(&ep->queue)) {
                                u32     s;

                                /* OUT FIFO might have packet(s) buffered */
                                s = readl(&ep->regs->ep_stat);
                                if ((s & BIT(FIFO_EMPTY)) == 0) {
                                        /* note:  _req->short_not_ok is
                                         * ignored here since PIO _always_
                                         * stops queue advance here, and
                                         * _req->status doesn't change for
                                         * short reads (only _req->actual)
                                         */
                                        if (read_fifo(ep, req) &&
                                                        ep->num == 0) {
                                                done(ep, req, 0);
                                                allow_status(ep);
                                                /* don't queue it */
                                                req = NULL;
                                        } else if (read_fifo(ep, req) &&
                                                        ep->num != 0) {
                                                done(ep, req, 0);
                                                req = NULL;
                                        } else
                                                s = readl(&ep->regs->ep_stat);
                                }

                                /* don't NAK, let the fifo fill */
                                if (req && (s & BIT(NAK_OUT_PACKETS)))
                                        writel(BIT(CLEAR_NAK_OUT_PACKETS),
                                                        &ep->regs->ep_rsp);
                        }
                }

        } else if (ep->dma) {
                int     valid = 1;

                if (ep->is_in) {
                        int     expect;

                        /* preventing magic zlps is per-engine state, not
                         * per-transfer; irq logic must recover hiccups.
                         */
                        expect = likely(req->req.zero ||
                                (req->req.length % ep->ep.maxpacket));
                        if (expect != ep->in_fifo_validate)
                                valid = 0;
                }
                queue_dma(ep, req, valid);

        } /* else the irq handler advances the queue. */

        ep->responded = 1;
        if (req)
                list_add_tail(&req->queue, &ep->queue);
done:
        spin_unlock_irqrestore(&dev->lock, flags);

        /* pci writes may still be posted */
        return ret;

print_err:
        dev_err(&ep->dev->pdev->dev, "%s: error=%d\n", __func__, ret);
        return ret;
}

static inline void
dma_done(struct net2280_ep *ep, struct net2280_request *req, u32 dmacount,
                int status)
{
        req->req.actual = req->req.length - (DMA_BYTE_COUNT_MASK & dmacount);
        done(ep, req, status);
}

static int scan_dma_completions(struct net2280_ep *ep)
{
        int num_completed = 0;

        /* only look at descriptors that were "naturally" retired,
         * so fifo and list head state won't matter
         */
        while (!list_empty(&ep->queue)) {
                struct net2280_request  *req;
                u32 req_dma_count;

                req = list_entry(ep->queue.next,
                                struct net2280_request, queue);
                if (!req->valid)
                        break;
                rmb();
                req_dma_count = le32_to_cpup(&req->td->dmacount);
                if ((req_dma_count & BIT(VALID_BIT)) != 0)
                        break;

                /* SHORT_PACKET_TRANSFERRED_INTERRUPT handles "usb-short"
                 * cases where DMA must be aborted; this code handles
                 * all non-abort DMA completions.
                 */
                if (unlikely(req->td->dmadesc == 0)) {
                        /* paranoia */
                        u32 const ep_dmacount = readl(&ep->dma->dmacount);

                        if (ep_dmacount & DMA_BYTE_COUNT_MASK)
                                break;
                        /* single transfer mode */
                        dma_done(ep, req, req_dma_count, 0);
                        num_completed++;
                        break;
                } else if (!ep->is_in &&
                           (req->req.length % ep->ep.maxpacket) &&
                           !(ep->dev->quirks & PLX_PCIE)) {

                        u32 const ep_stat = readl(&ep->regs->ep_stat);
                        /* AVOID TROUBLE HERE by not issuing short reads from
                         * your gadget driver.  That helps avoids errata 0121,
                         * 0122, and 0124; not all cases trigger the warning.
                         */
                        if ((ep_stat & BIT(NAK_OUT_PACKETS)) == 0) {
                                ep_warn(ep->dev, "%s lost packet sync!\n",
                                                ep->ep.name);
                                req->req.status = -EOVERFLOW;
                        } else {
                                u32 const ep_avail = readl(&ep->regs->ep_avail);
                                if (ep_avail) {
                                        /* fifo gets flushed later */
                                        ep->out_overflow = 1;
                                        ep_dbg(ep->dev,
                                                "%s dma, discard %d len %d\n",
                                                ep->ep.name, ep_avail,
                                                req->req.length);
                                        req->req.status = -EOVERFLOW;
                                }
                        }
                }
                dma_done(ep, req, req_dma_count, 0);
                num_completed++;
        }

        return num_completed;
}

static void restart_dma(struct net2280_ep *ep)
{
        struct net2280_request  *req;

        if (ep->stopped)
                return;
        req = list_entry(ep->queue.next, struct net2280_request, queue);

        start_dma(ep, req);
}

static void abort_dma(struct net2280_ep *ep)
{
        /* abort the current transfer */
        if (likely(!list_empty(&ep->queue))) {
                /* FIXME work around errata 0121, 0122, 0124 */
                writel(BIT(DMA_ABORT), &ep->dma->dmastat);
                spin_stop_dma(ep->dma);
        } else
                stop_dma(ep->dma);
        scan_dma_completions(ep);
}

/* dequeue ALL requests */
static void nuke(struct net2280_ep *ep)
{
        struct net2280_request  *req;

        /* called with spinlock held */
        ep->stopped = 1;
        if (ep->dma)
                abort_dma(ep);
        while (!list_empty(&ep->queue)) {
                req = list_entry(ep->queue.next,
                                struct net2280_request,
                                queue);
                done(ep, req, -ESHUTDOWN);
        }
}

/* dequeue JUST ONE request */
static int net2280_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
        struct net2280_ep       *ep;
        struct net2280_request  *req;
        unsigned long           flags;
        u32                     dmactl;
        int                     stopped;

        ep = container_of(_ep, struct net2280_ep, ep);
        if (!_ep || (!ep->desc && ep->num != 0) || !_req) {
                pr_err("%s: Invalid ep=%p or ep->desc or req=%p\n",
                                                __func__, _ep, _req);
                return -EINVAL;
        }

        spin_lock_irqsave(&ep->dev->lock, flags);
        stopped = ep->stopped;

        /* quiesce dma while we patch the queue */
        dmactl = 0;
        ep->stopped = 1;
        if (ep->dma) {
                dmactl = readl(&ep->dma->dmactl);
                /* WARNING erratum 0127 may kick in ... */
                stop_dma(ep->dma);
                scan_dma_completions(ep);
        }

        /* make sure it's still queued on this endpoint */
        list_for_each_entry(req, &ep->queue, queue) {
                if (&req->req == _req)
                        break;
        }
        if (&req->req != _req) {
                spin_unlock_irqrestore(&ep->dev->lock, flags);
                dev_err(&ep->dev->pdev->dev, "%s: Request mismatch\n",
                                                                __func__);
                return -EINVAL;
        }

        /* queue head may be partially complete. */
        if (ep->queue.next == &req->queue) {
                if (ep->dma) {
                        ep_dbg(ep->dev, "unlink (%s) dma\n", _ep->name);
                        _req->status = -ECONNRESET;
                        abort_dma(ep);
                        if (likely(ep->queue.next == &req->queue)) {
                                /* NOTE: misreports single-transfer mode*/
                                req->td->dmacount = 0;  /* invalidate */
                                dma_done(ep, req,
                                        readl(&ep->dma->dmacount),
                                        -ECONNRESET);
                        }
                } else {
                        ep_dbg(ep->dev, "unlink (%s) pio\n", _ep->name);
                        done(ep, req, -ECONNRESET);
                }
                req = NULL;
        }

        if (req)
                done(ep, req, -ECONNRESET);
        ep->stopped = stopped;

        if (ep->dma) {
                /* turn off dma on inactive queues */
                if (list_empty(&ep->queue))
                        stop_dma(ep->dma);
                else if (!ep->stopped) {
                        /* resume current request, or start new one */
                        if (req)
                                writel(dmactl, &ep->dma->dmactl);
                        else
                                start_dma(ep, list_entry(ep->queue.next,
                                        struct net2280_request, queue));
                }
        }

        spin_unlock_irqrestore(&ep->dev->lock, flags);
        return 0;
}

/*-------------------------------------------------------------------------*/

static int net2280_fifo_status(struct usb_ep *_ep);

static int
net2280_set_halt_and_wedge(struct usb_ep *_ep, int value, int wedged)
{
        struct net2280_ep       *ep;
        unsigned long           flags;
        int                     retval = 0;

        ep = container_of(_ep, struct net2280_ep, ep);
        if (!_ep || (!ep->desc && ep->num != 0)) {
                pr_err("%s: Invalid ep=%p or ep->desc\n", __func__, _ep);
                return -EINVAL;
        }
        if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN) {
                retval = -ESHUTDOWN;
                goto print_err;
        }
        if (ep->desc /* not ep0 */ && (ep->desc->bmAttributes & 0x03)
                                                == USB_ENDPOINT_XFER_ISOC) {
                retval = -EINVAL;
                goto print_err;
        }

        spin_lock_irqsave(&ep->dev->lock, flags);
        if (!list_empty(&ep->queue)) {
                retval = -EAGAIN;
                goto print_unlock;
        } else if (ep->is_in && value && net2280_fifo_status(_ep) != 0) {
                retval = -EAGAIN;
                goto print_unlock;
        } else {
                ep_vdbg(ep->dev, "%s %s %s\n", _ep->name,
                                value ? "set" : "clear",
                                wedged ? "wedge" : "halt");
                /* set/clear, then synch memory views with the device */
                if (value) {
                        if (ep->num == 0)
                                ep->dev->protocol_stall = 1;
                        else
                                set_halt(ep);
                        if (wedged)
                                ep->wedged = 1;
                } else {
                        clear_halt(ep);
                        if (ep->dev->quirks & PLX_PCIE &&
                                !list_empty(&ep->queue) && ep->td_dma)
                                        restart_dma(ep);
                        ep->wedged = 0;
                }
                (void) readl(&ep->regs->ep_rsp);
        }
        spin_unlock_irqrestore(&ep->dev->lock, flags);

        return retval;

print_unlock:
        spin_unlock_irqrestore(&ep->dev->lock, flags);
print_err:
        dev_err(&ep->dev->pdev->dev, "%s: error=%d\n", __func__, retval);
        return retval;
}

static int net2280_set_halt(struct usb_ep *_ep, int value)
{
        return net2280_set_halt_and_wedge(_ep, value, 0);
}

static int net2280_set_wedge(struct usb_ep *_ep)
{
        if (!_ep || _ep->name == ep0name) {
                pr_err("%s: Invalid ep=%p or ep0\n", __func__, _ep);
                return -EINVAL;
        }
        return net2280_set_halt_and_wedge(_ep, 1, 1);
}

static int net2280_fifo_status(struct usb_ep *_ep)
{
        struct net2280_ep       *ep;
        u32                     avail;

        ep = container_of(_ep, struct net2280_ep, ep);
        if (!_ep || (!ep->desc && ep->num != 0)) {
                pr_err("%s: Invalid ep=%p or ep->desc\n", __func__, _ep);
                return -ENODEV;
        }
        if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN) {
                dev_err(&ep->dev->pdev->dev,
                        "%s: Invalid driver=%p or speed=%d\n",
                        __func__, ep->dev->driver, ep->dev->gadget.speed);
                return -ESHUTDOWN;
        }

        avail = readl(&ep->regs->ep_avail) & (BIT(12) - 1);
        if (avail > ep->fifo_size) {
                dev_err(&ep->dev->pdev->dev, "%s: Fifo overflow\n", __func__);
                return -EOVERFLOW;
        }
        if (ep->is_in)
                avail = ep->fifo_size - avail;
        return avail;
}

static void net2280_fifo_flush(struct usb_ep *_ep)
{
        struct net2280_ep       *ep;

        ep = container_of(_ep, struct net2280_ep, ep);
        if (!_ep || (!ep->desc && ep->num != 0)) {
                pr_err("%s: Invalid ep=%p or ep->desc\n", __func__, _ep);
                return;
        }
        if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN) {
                dev_err(&ep->dev->pdev->dev,
                        "%s: Invalid driver=%p or speed=%d\n",
                        __func__, ep->dev->driver, ep->dev->gadget.speed);
                return;
        }

        writel(BIT(FIFO_FLUSH), &ep->regs->ep_stat);
        (void) readl(&ep->regs->ep_rsp);
}

static const struct usb_ep_ops net2280_ep_ops = {
        .enable         = net2280_enable,
        .disable        = net2280_disable,

        .alloc_request  = net2280_alloc_request,
        .free_request   = net2280_free_request,

        .queue          = net2280_queue,
        .dequeue        = net2280_dequeue,

        .set_halt       = net2280_set_halt,
        .set_wedge      = net2280_set_wedge,
        .fifo_status    = net2280_fifo_status,
        .fifo_flush     = net2280_fifo_flush,
};

/*-------------------------------------------------------------------------*/

static int net2280_get_frame(struct usb_gadget *_gadget)
{
        struct net2280          *dev;
        unsigned long           flags;
        u16                     retval;

        if (!_gadget)
                return -ENODEV;
        dev = container_of(_gadget, struct net2280, gadget);
        spin_lock_irqsave(&dev->lock, flags);
        retval = get_idx_reg(dev->regs, REG_FRAME) & 0x03ff;
        spin_unlock_irqrestore(&dev->lock, flags);
        return retval;
}

static int net2280_wakeup(struct usb_gadget *_gadget)
{
        struct net2280          *dev;
        u32                     tmp;
        unsigned long           flags;

        if (!_gadget)
                return 0;
        dev = container_of(_gadget, struct net2280, gadget);

        spin_lock_irqsave(&dev->lock, flags);
        tmp = readl(&dev->usb->usbctl);
        if (tmp & BIT(DEVICE_REMOTE_WAKEUP_ENABLE))
                writel(BIT(GENERATE_RESUME), &dev->usb->usbstat);
        spin_unlock_irqrestore(&dev->lock, flags);

        /* pci writes may still be posted */
        return 0;
}

static int net2280_set_selfpowered(struct usb_gadget *_gadget, int value)
{
        struct net2280          *dev;
        u32                     tmp;
        unsigned long           flags;

        if (!_gadget)
                return 0;
        dev = container_of(_gadget, struct net2280, gadget);

        spin_lock_irqsave(&dev->lock, flags);
        tmp = readl(&dev->usb->usbctl);
        if (value) {
                tmp |= BIT(SELF_POWERED_STATUS);
                _gadget->is_selfpowered = 1;
        } else {
                tmp &= ~BIT(SELF_POWERED_STATUS);
                _gadget->is_selfpowered = 0;
        }
        writel(tmp, &dev->usb->usbctl);
        spin_unlock_irqrestore(&dev->lock, flags);

        return 0;
}

static int net2280_pullup(struct usb_gadget *_gadget, int is_on)
{
        struct net2280  *dev;
        u32             tmp;
        unsigned long   flags;

        if (!_gadget)
                return -ENODEV;
        dev = container_of(_gadget, struct net2280, gadget);

        spin_lock_irqsave(&dev->lock, flags);
        tmp = readl(&dev->usb->usbctl);
        dev->softconnect = (is_on != 0);
        if (is_on) {
                ep0_start(dev);
                writel(tmp | BIT(USB_DETECT_ENABLE), &dev->usb->usbctl);
        } else {
                writel(tmp & ~BIT(USB_DETECT_ENABLE), &dev->usb->usbctl);
                stop_activity(dev, NULL);
        }

        spin_unlock_irqrestore(&dev->lock, flags);

        return 0;
}

static struct usb_ep *net2280_match_ep(struct usb_gadget *_gadget,
                struct usb_endpoint_descriptor *desc,
                struct usb_ss_ep_comp_descriptor *ep_comp)
{
        char name[8];
        struct usb_ep *ep;

        if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_INT) {
                /* ep-e, ep-f are PIO with only 64 byte fifos */
                ep = gadget_find_ep_by_name(_gadget, "ep-e");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
                ep = gadget_find_ep_by_name(_gadget, "ep-f");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
        }

        /* USB3380: Only first four endpoints have DMA channels. Allocate
         * slower interrupt endpoints from PIO hw endpoints, to allow bulk/isoc
         * endpoints use DMA hw endpoints.
         */
        if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_INT &&
            usb_endpoint_dir_in(desc)) {
                ep = gadget_find_ep_by_name(_gadget, "ep2in");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
                ep = gadget_find_ep_by_name(_gadget, "ep4in");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
        } else if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_INT &&
                   !usb_endpoint_dir_in(desc)) {
                ep = gadget_find_ep_by_name(_gadget, "ep1out");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
                ep = gadget_find_ep_by_name(_gadget, "ep3out");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
        } else if (usb_endpoint_type(desc) != USB_ENDPOINT_XFER_BULK &&
                   usb_endpoint_dir_in(desc)) {
                ep = gadget_find_ep_by_name(_gadget, "ep1in");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
                ep = gadget_find_ep_by_name(_gadget, "ep3in");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
        } else if (usb_endpoint_type(desc) != USB_ENDPOINT_XFER_BULK &&
                   !usb_endpoint_dir_in(desc)) {
                ep = gadget_find_ep_by_name(_gadget, "ep2out");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
                ep = gadget_find_ep_by_name(_gadget, "ep4out");
                if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                        return ep;
        }

        /* USB3380: use same address for usb and hardware endpoints */
        snprintf(name, sizeof(name), "ep%d%s", usb_endpoint_num(desc),
                        usb_endpoint_dir_in(desc) ? "in" : "out");
        ep = gadget_find_ep_by_name(_gadget, name);
        if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp))
                return ep;

        return NULL;
}

static int net2280_start(struct usb_gadget *_gadget,
                struct usb_gadget_driver *driver);
static int net2280_stop(struct usb_gadget *_gadget);

static const struct usb_gadget_ops net2280_ops = {
        .get_frame      = net2280_get_frame,
        .wakeup         = net2280_wakeup,
        .set_selfpowered = net2280_set_selfpowered,
        .pullup         = net2280_pullup,
        .udc_start      = net2280_start,
        .udc_stop       = net2280_stop,
        .match_ep       = net2280_match_ep,
};

/*-------------------------------------------------------------------------*/

#ifdef  CONFIG_USB_GADGET_DEBUG_FILES

/* FIXME move these into procfs, and use seq_file.
 * Sysfs _still_ doesn't behave for arbitrarily sized files,
 * and also doesn't help products using this with 2.4 kernels.
 */

/* "function" sysfs attribute */
static ssize_t function_show(struct device *_dev, struct device_attribute *attr,
                             char *buf)
{
        struct net2280  *dev = dev_get_drvdata(_dev);

        if (!dev->driver || !dev->driver->function ||
                        strlen(dev->driver->function) > PAGE_SIZE)
                return 0;
        return scnprintf(buf, PAGE_SIZE, "%s\n", dev->driver->function);
}
static DEVICE_ATTR_RO(function);

static ssize_t registers_show(struct device *_dev,
                              struct device_attribute *attr, char *buf)
{
        struct net2280          *dev;
        char                    *next;
        unsigned                size, t;
        unsigned long           flags;
        int                     i;
        u32                     t1, t2;
        const char              *s;

        dev = dev_get_drvdata(_dev);
        next = buf;
        size = PAGE_SIZE;
        spin_lock_irqsave(&dev->lock, flags);

        if (dev->driver)
                s = dev->driver->driver.name;
        else
                s = "(none)";

        /* Main Control Registers */
        t = scnprintf(next, size, "%s version " DRIVER_VERSION
                        ", chiprev %04x\n\n"
                        "devinit %03x fifoctl %08x gadget '%s'\n"
                        "pci irqenb0 %02x irqenb1 %08x "
                        "irqstat0 %04x irqstat1 %08x\n",
                        driver_name, dev->chiprev,
                        readl(&dev->regs->devinit),
                        readl(&dev->regs->fifoctl),
                        s,
                        readl(&dev->regs->pciirqenb0),
                        readl(&dev->regs->pciirqenb1),
                        readl(&dev->regs->irqstat0),
                        readl(&dev->regs->irqstat1));
        size -= t;
        next += t;

        /* USB Control Registers */
        t1 = readl(&dev->usb->usbctl);
        t2 = readl(&dev->usb->usbstat);
        if (t1 & BIT(VBUS_PIN)) {
                if (t2 & BIT(HIGH_SPEED))
                        s = "high speed";
                else if (dev->gadget.speed == USB_SPEED_UNKNOWN)
                        s = "powered";
                else
                        s = "full speed";
                /* full speed bit (6) not working?? */
        } else
                        s = "not attached";
        t = scnprintf(next, size,
                        "stdrsp %08x usbctl %08x usbstat %08x "
                                "addr 0x%02x (%s)\n",
                        readl(&dev->usb->stdrsp), t1, t2,
                        readl(&dev->usb->ouraddr), s);
        size -= t;
        next += t;

        /* PCI Master Control Registers */

        /* DMA Control Registers */

        /* Configurable EP Control Registers */
        for (i = 0; i < dev->n_ep; i++) {
                struct net2280_ep       *ep;

                ep = &dev->ep[i];
                if (i && !ep->desc)
                        continue;

                t1 = readl(&ep->cfg->ep_cfg);
                t2 = readl(&ep->regs->ep_rsp) & 0xff;
                t = scnprintf(next, size,
                                "\n%s\tcfg %05x rsp (%02x) %s%s%s%s%s%s%s%s"
                                        "irqenb %02x\n",
                                ep->ep.name, t1, t2,
                                (t2 & BIT(CLEAR_NAK_OUT_PACKETS))
                                        ? "NAK " : "",
                                (t2 & BIT(CLEAR_EP_HIDE_STATUS_PHASE))
                                        ? "hide " : "",
                                (t2 & BIT(CLEAR_EP_FORCE_CRC_ERROR))
                                        ? "CRC " : "",
                                (t2 & BIT(CLEAR_INTERRUPT_MODE))
                                        ? "interrupt " : "",
                                (t2 & BIT(CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE))
                                        ? "status " : "",
                                (t2 & BIT(CLEAR_NAK_OUT_PACKETS_MODE))
                                        ? "NAKmode " : "",
                                (t2 & BIT(CLEAR_ENDPOINT_TOGGLE))
                                        ? "DATA1 " : "DATA0 ",
                                (t2 & BIT(CLEAR_ENDPOINT_HALT))
                                        ? "HALT " : "",
                                readl(&ep->regs->ep_irqenb));
                size -= t;
                next += t;

                t = scnprintf(next, size,
                                "\tstat %08x avail %04x "
                                "(ep%d%s-%s)%s\n",
                                readl(&ep->regs->ep_stat),
                                readl(&ep->regs->ep_avail),
                                t1 & 0x0f, DIR_STRING(t1),
                                type_string(t1 >> 8),
                                ep->stopped ? "*" : "");
                size -= t;
                next += t;

                if (!ep->dma)
                        continue;

                t = scnprintf(next, size,
                                "  dma\tctl %08x stat %08x count %08x\n"
                                "\taddr %08x desc %08x\n",
                                readl(&ep->dma->dmactl),
                                readl(&ep->dma->dmastat),
                                readl(&ep->dma->dmacount),
                                readl(&ep->dma->dmaaddr),
                                readl(&ep->dma->dmadesc));
                size -= t;
                next += t;

        }

        /* Indexed Registers (none yet) */

        /* Statistics */
        t = scnprintf(next, size, "\nirqs:  ");
        size -= t;
        next += t;
        for (i = 0; i < dev->n_ep; i++) {
                struct net2280_ep       *ep;

                ep = &dev->ep[i];
                if (i && !ep->irqs)
                        continue;
                t = scnprintf(next, size, " %s/%lu", ep->ep.name, ep->irqs);
                size -= t;
                next += t;

        }
        t = scnprintf(next, size, "\n");
        size -= t;
        next += t;

        spin_unlock_irqrestore(&dev->lock, flags);

        return PAGE_SIZE - size;
}
static DEVICE_ATTR_RO(registers);

static ssize_t queues_show(struct device *_dev, struct device_attribute *attr,
                           char *buf)
{
        struct net2280          *dev;
        char                    *next;
        unsigned                size;
        unsigned long           flags;
        int                     i;

        dev = dev_get_drvdata(_dev);
        next = buf;
        size = PAGE_SIZE;
        spin_lock_irqsave(&dev->lock, flags);

        for (i = 0; i < dev->n_ep; i++) {
                struct net2280_ep               *ep = &dev->ep[i];
                struct net2280_request          *req;
                int                             t;

                if (i != 0) {
                        const struct usb_endpoint_descriptor    *d;

                        d = ep->desc;
                        if (!d)
                                continue;
                        t = d->bEndpointAddress;
                        t = scnprintf(next, size,
                                "\n%s (ep%d%s-%s) max %04x %s fifo %d\n",
                                ep->ep.name, t & USB_ENDPOINT_NUMBER_MASK,
                                (t & USB_DIR_IN) ? "in" : "out",
                                type_string(d->bmAttributes),
                                usb_endpoint_maxp(d),
                                ep->dma ? "dma" : "pio", ep->fifo_size
                                );
                } else /* ep0 should only have one transfer queued */
                        t = scnprintf(next, size, "ep0 max 64 pio %s\n",
                                        ep->is_in ? "in" : "out");
                if (t <= 0 || t > size)
                        goto done;
                size -= t;
                next += t;

                if (list_empty(&ep->queue)) {
                        t = scnprintf(next, size, "\t(nothing queued)\n");
                        if (t <= 0 || t > size)
                                goto done;
                        size -= t;
                        next += t;
                        continue;
                }
                list_for_each_entry(req, &ep->queue, queue) {
                        if (ep->dma && req->td_dma == readl(&ep->dma->dmadesc))
                                t = scnprintf(next, size,
                                        "\treq %p len %d/%d "
                                        "buf %p (dmacount %08x)\n",
                                        &req->req, req->req.actual,
                                        req->req.length, req->req.buf,
                                        readl(&ep->dma->dmacount));
                        else
                                t = scnprintf(next, size,
                                        "\treq %p len %d/%d buf %p\n",
                                        &req->req, req->req.actual,
                                        req->req.length, req->req.buf);
                        if (t <= 0 || t > size)
                                goto done;
                        size -= t;
                        next += t;

                        if (ep->dma) {
                                struct net2280_dma      *td;

                                td = req->td;
                                t = scnprintf(next, size, "\t    td %08x "
                                        " count %08x buf %08x desc %08x\n",
                                        (u32) req->td_dma,
                                        le32_to_cpu(td->dmacount),
                                        le32_to_cpu(td->dmaaddr),
                                        le32_to_cpu(td->dmadesc));
                                if (t <= 0 || t > size)
                                        goto done;
                                size -= t;
                                next += t;
                        }
                }
        }

done:
        spin_unlock_irqrestore(&dev->lock, flags);
        return PAGE_SIZE - size;
}
static DEVICE_ATTR_RO(queues);


#else

#define device_create_file(a, b)        (0)
#define device_remove_file(a, b)        do { } while (0)

#endif

/*-------------------------------------------------------------------------*/

/* another driver-specific mode might be a request type doing dma
 * to/from another device fifo instead of to/from memory.
 */

static void set_fifo_mode(struct net2280 *dev, int mode)
{
        /* keeping high bits preserves BAR2 */
        writel((0xffff << PCI_BASE2_RANGE) | mode, &dev->regs->fifoctl);

        /* always ep-{a,b,e,f} ... maybe not ep-c or ep-d */
        INIT_LIST_HEAD(&dev->gadget.ep_list);
        list_add_tail(&dev->ep[1].ep.ep_list, &dev->gadget.ep_list);
        list_add_tail(&dev->ep[2].ep.ep_list, &dev->gadget.ep_list);
        switch (mode) {
        case 0:
                list_add_tail(&dev->ep[3].ep.ep_list, &dev->gadget.ep_list);
                list_add_tail(&dev->ep[4].ep.ep_list, &dev->gadget.ep_list);
                dev->ep[1].fifo_size = dev->ep[2].fifo_size = 1024;
                break;
        case 1:
                dev->ep[1].fifo_size = dev->ep[2].fifo_size = 2048;
                break;
        case 2:
                list_add_tail(&dev->ep[3].ep.ep_list, &dev->gadget.ep_list);
                dev->ep[1].fifo_size = 2048;
                dev->ep[2].fifo_size = 1024;
                break;
        }
        /* fifo sizes for ep0, ep-c, ep-d, ep-e, and ep-f never change */
        list_add_tail(&dev->ep[5].ep.ep_list, &dev->gadget.ep_list);
        list_add_tail(&dev->ep[6].ep.ep_list, &dev->gadget.ep_list);
}

static void defect7374_disable_data_eps(struct net2280 *dev)
{
        /*
         * For Defect 7374, disable data EPs (and more):
         *  - This phase undoes the earlier phase of the Defect 7374 workaround,
         *    returing ep regs back to normal.
         */
        struct net2280_ep *ep;
        int i;
        unsigned char ep_sel;
        u32 tmp_reg;

        for (i = 1; i < 5; i++) {
                ep = &dev->ep[i];
                writel(i, &ep->cfg->ep_cfg);
        }

        /* CSROUT, CSRIN, PCIOUT, PCIIN, STATIN, RCIN */
        for (i = 0; i < 6; i++)
                writel(0, &dev->dep[i].dep_cfg);

        for (ep_sel = 0; ep_sel <= 21; ep_sel++) {
                /* Select an endpoint for subsequent operations: */
                tmp_reg = readl(&dev->plregs->pl_ep_ctrl);
                writel(((tmp_reg & ~0x1f) | ep_sel), &dev->plregs->pl_ep_ctrl);

                if (ep_sel < 2 || (ep_sel > 9 && ep_sel < 14) ||
                                        ep_sel == 18 || ep_sel == 20)
                        continue;

                /* Change settings on some selected endpoints */
                tmp_reg = readl(&dev->plregs->pl_ep_cfg_4);
                tmp_reg &= ~BIT(NON_CTRL_IN_TOLERATE_BAD_DIR);
                writel(tmp_reg, &dev->plregs->pl_ep_cfg_4);
                tmp_reg = readl(&dev->plregs->pl_ep_ctrl);
                tmp_reg |= BIT(EP_INITIALIZED);
                writel(tmp_reg, &dev->plregs->pl_ep_ctrl);
        }
}

static void defect7374_enable_data_eps_zero(struct net2280 *dev)
{
        u32 tmp = 0, tmp_reg;
        u32 scratch;
        int i;
        unsigned char ep_sel;

        scratch = get_idx_reg(dev->regs, SCRATCH);

        WARN_ON((scratch & (0xf << DEFECT7374_FSM_FIELD))
                == DEFECT7374_FSM_SS_CONTROL_READ);

        scratch &= ~(0xf << DEFECT7374_FSM_FIELD);

        ep_warn(dev, "Operate Defect 7374 workaround soft this time");
        ep_warn(dev, "It will operate on cold-reboot and SS connect");

        /*GPEPs:*/

        tmp = ((0 << ENDPOINT_NUMBER) | BIT(ENDPOINT_DIRECTION) |
                        (2 << OUT_ENDPOINT_TYPE) | (2 << IN_ENDPOINT_TYPE) |
                        ((dev->enhanced_mode) ?
                         BIT(OUT_ENDPOINT_ENABLE) | BIT(IN_ENDPOINT_ENABLE) :
                         BIT(ENDPOINT_ENABLE)));

        for (i = 1; i < 5; i++)
                writel(tmp, &dev->ep[i].cfg->ep_cfg);

        /* CSRIN, PCIIN, STATIN, RCIN*/
        tmp = ((0 << ENDPOINT_NUMBER) | BIT(ENDPOINT_ENABLE));
        writel(tmp, &dev->dep[1].dep_cfg);
        writel(tmp, &dev->dep[3].dep_cfg);
        writel(tmp, &dev->dep[4].dep_cfg);
        writel(tmp, &dev->dep[5].dep_cfg);

        /*Implemented for development and debug.
         * Can be refined/tuned later.*/
        for (ep_sel = 0; ep_sel <= 21; ep_sel++) {
                /* Select an endpoint for subsequent operations: */
                tmp_reg = readl(&dev->plregs->pl_ep_ctrl);
                writel(((tmp_reg & ~0x1f) | ep_sel),
                                &dev->plregs->pl_ep_ctrl);

                if (ep_sel == 1) {
                        tmp =
                                (readl(&dev->plregs->pl_ep_ctrl) |
                                 BIT(CLEAR_ACK_ERROR_CODE) | 0);
                        writel(tmp, &dev->plregs->pl_ep_ctrl);
                        continue;
                }

                if (ep_sel == 0 || (ep_sel > 9 && ep_sel < 14) ||
                                ep_sel == 18  || ep_sel == 20)
                        continue;

                tmp = (readl(&dev->plregs->pl_ep_cfg_4) |
                                BIT(NON_CTRL_IN_TOLERATE_BAD_DIR) | 0);
                writel(tmp, &dev->plregs->pl_ep_cfg_4);

                tmp = readl(&dev->plregs->pl_ep_ctrl) &
                        ~BIT(EP_INITIALIZED);
                writel(tmp, &dev->plregs->pl_ep_ctrl);

        }

        /* Set FSM to focus on the first Control Read:
         * - Tip: Connection speed is known upon the first
         * setup request.*/
        scratch |= DEFECT7374_FSM_WAITING_FOR_CONTROL_READ;
        set_idx_reg(dev->regs, SCRATCH, scratch);

}

/* keeping it simple:
 * - one bus driver, initted first;
 * - one function driver, initted second
 *
 * most of the work to support multiple net2280 controllers would
 * be to associate this gadget driver (yes?) with all of them, or
 * perhaps to bind specific drivers to specific devices.
 */

static void usb_reset_228x(struct net2280 *dev)
{
        u32     tmp;

        dev->gadget.speed = USB_SPEED_UNKNOWN;
        (void) readl(&dev->usb->usbctl);

        net2280_led_init(dev);

        /* disable automatic responses, and irqs */
        writel(0, &dev->usb->stdrsp);
        writel(0, &dev->regs->pciirqenb0);
        writel(0, &dev->regs->pciirqenb1);

        /* clear old dma and irq state */
        for (tmp = 0; tmp < 4; tmp++) {
                struct net2280_ep       *ep = &dev->ep[tmp + 1];
                if (ep->dma)
                        abort_dma(ep);
        }

        writel(~0, &dev->regs->irqstat0),
        writel(~(u32)BIT(SUSPEND_REQUEST_INTERRUPT), &dev->regs->irqstat1),

        /* reset, and enable pci */
        tmp = readl(&dev->regs->devinit) |
                BIT(PCI_ENABLE) |
                BIT(FIFO_SOFT_RESET) |
                BIT(USB_SOFT_RESET) |
                BIT(M8051_RESET);
        writel(tmp, &dev->regs->devinit);

        /* standard fifo and endpoint allocations */
        set_fifo_mode(dev, (fifo_mode <= 2) ? fifo_mode : 0);
}

static void usb_reset_338x(struct net2280 *dev)
{
        u32 tmp;

        dev->gadget.speed = USB_SPEED_UNKNOWN;
        (void)readl(&dev->usb->usbctl);

        net2280_led_init(dev);

        if (dev->bug7734_patched) {
                /* disable automatic responses, and irqs */
                writel(0, &dev->usb->stdrsp);
                writel(0, &dev->regs->pciirqenb0);
                writel(0, &dev->regs->pciirqenb1);
        }

        /* clear old dma and irq state */
        for (tmp = 0; tmp < 4; tmp++) {
                struct net2280_ep *ep = &dev->ep[tmp + 1];
                struct net2280_dma_regs __iomem *dma;

                if (ep->dma) {
                        abort_dma(ep);
                } else {
                        dma = &dev->dma[tmp];
                        writel(BIT(DMA_ABORT), &dma->dmastat);
                        writel(0, &dma->dmactl);
                }
        }

        writel(~0, &dev->regs->irqstat0), writel(~0, &dev->regs->irqstat1);

        if (dev->bug7734_patched) {
                /* reset, and enable pci */
                tmp = readl(&dev->regs->devinit) |
                    BIT(PCI_ENABLE) |
                    BIT(FIFO_SOFT_RESET) |
                    BIT(USB_SOFT_RESET) |
                    BIT(M8051_RESET);

                writel(tmp, &dev->regs->devinit);
        }

        /* always ep-{1,2,3,4} ... maybe not ep-3 or ep-4 */
        INIT_LIST_HEAD(&dev->gadget.ep_list);

        for (tmp = 1; tmp < dev->n_ep; tmp++)
                list_add_tail(&dev->ep[tmp].ep.ep_list, &dev->gadget.ep_list);

}

static void usb_reset(struct net2280 *dev)
{
        if (dev->quirks & PLX_LEGACY)
                return usb_reset_228x(dev);
        return usb_reset_338x(dev);
}

static void usb_reinit_228x(struct net2280 *dev)
{
        u32     tmp;

        /* basic endpoint init */
        for (tmp = 0; tmp < 7; tmp++) {
                struct net2280_ep       *ep = &dev->ep[tmp];

                ep->ep.name = ep_info_dft[tmp].name;
                ep->ep.caps = ep_info_dft[tmp].caps;
                ep->dev = dev;
                ep->num = tmp;

                if (tmp > 0 && tmp <= 4) {
                        ep->fifo_size = 1024;
                        ep->dma = &dev->dma[tmp - 1];
                } else
                        ep->fifo_size = 64;
                ep->regs = &dev->epregs[tmp];
                ep->cfg = &dev->epregs[tmp];
                ep_reset_228x(dev->regs, ep);
        }
        usb_ep_set_maxpacket_limit(&dev->ep[0].ep, 64);
        usb_ep_set_maxpacket_limit(&dev->ep[5].ep, 64);
        usb_ep_set_maxpacket_limit(&dev->ep[6].ep, 64);

        dev->gadget.ep0 = &dev->ep[0].ep;
        dev->ep[0].stopped = 0;
        INIT_LIST_HEAD(&dev->gadget.ep0->ep_list);

        /* we want to prevent lowlevel/insecure access from the USB host,
         * but erratum 0119 means this enable bit is ignored
         */
        for (tmp = 0; tmp < 5; tmp++)
                writel(EP_DONTUSE, &dev->dep[tmp].dep_cfg);
}

static void usb_reinit_338x(struct net2280 *dev)
{
        int i;
        u32 tmp, val;
        static const u32 ne[9] = { 0, 1, 2, 3, 4, 1, 2, 3, 4 };
        static const u32 ep_reg_addr[9] = { 0x00, 0xC0, 0x00, 0xC0, 0x00,
                                                0x00, 0xC0, 0x00, 0xC0 };

        /* basic endpoint init */
        for (i = 0; i < dev->n_ep; i++) {
                struct net2280_ep *ep = &dev->ep[i];

                ep->ep.name = dev->enhanced_mode ? ep_info_adv[i].name :
                                                   ep_info_dft[i].name;
                ep->ep.caps = dev->enhanced_mode ? ep_info_adv[i].caps :
                                                   ep_info_dft[i].caps;
                ep->dev = dev;
                ep->num = i;

                if (i > 0 && i <= 4)
                        ep->dma = &dev->dma[i - 1];

                if (dev->enhanced_mode) {
                        ep->cfg = &dev->epregs[ne[i]];
                        /*
                         * Set USB endpoint number, hardware allows same number
                         * in both directions.
                         */
                         if (i > 0 && i < 5)
                                writel(ne[i], &ep->cfg->ep_cfg);
                        ep->regs = (struct net2280_ep_regs __iomem *)
                                (((void __iomem *)&dev->epregs[ne[i]]) +
                                ep_reg_addr[i]);
                } else {
                        ep->cfg = &dev->epregs[i];
                        ep->regs = &dev->epregs[i];
                }

                ep->fifo_size = (i != 0) ? 2048 : 512;

                ep_reset_338x(dev->regs, ep);
        }
        usb_ep_set_maxpacket_limit(&dev->ep[0].ep, 512);

        dev->gadget.ep0 = &dev->ep[0].ep;
        dev->ep[0].stopped = 0;

        /* Link layer set up */
        if (dev->bug7734_patched) {
                tmp = readl(&dev->usb_ext->usbctl2) &
                    ~(BIT(U1_ENABLE) | BIT(U2_ENABLE) | BIT(LTM_ENABLE));
                writel(tmp, &dev->usb_ext->usbctl2);
        }

        /* Hardware Defect and Workaround */
        val = readl(&dev->ll_lfps_regs->ll_lfps_5);
        val &= ~(0xf << TIMER_LFPS_6US);
        val |= 0x5 << TIMER_LFPS_6US;
        writel(val, &dev->ll_lfps_regs->ll_lfps_5);

        val = readl(&dev->ll_lfps_regs->ll_lfps_6);
        val &= ~(0xffff << TIMER_LFPS_80US);
        val |= 0x0100 << TIMER_LFPS_80US;
        writel(val, &dev->ll_lfps_regs->ll_lfps_6);

        /*
         * AA_AB Errata. Issue 4. Workaround for SuperSpeed USB
         * Hot Reset Exit Handshake may Fail in Specific Case using
         * Default Register Settings. Workaround for Enumeration test.
         */
        val = readl(&dev->ll_tsn_regs->ll_tsn_counters_2);
        val &= ~(0x1f << HOT_TX_NORESET_TS2);
        val |= 0x10 << HOT_TX_NORESET_TS2;
        writel(val, &dev->ll_tsn_regs->ll_tsn_counters_2);

        val = readl(&dev->ll_tsn_regs->ll_tsn_counters_3);
        val &= ~(0x1f << HOT_RX_RESET_TS2);
        val |= 0x3 << HOT_RX_RESET_TS2;
        writel(val, &dev->ll_tsn_regs->ll_tsn_counters_3);

        /*
         * Set Recovery Idle to Recover bit:
         * - On SS connections, setting Recovery Idle to Recover Fmw improves
         *   link robustness with various hosts and hubs.
         * - It is safe to set for all connection speeds; all chip revisions.
         * - R-M-W to leave other bits undisturbed.
         * - Reference PLX TT-7372
        */
        val = readl(&dev->ll_chicken_reg->ll_tsn_chicken_bit);
        val |= BIT(RECOVERY_IDLE_TO_RECOVER_FMW);
        writel(val, &dev->ll_chicken_reg->ll_tsn_chicken_bit);

        INIT_LIST_HEAD(&dev->gadget.ep0->ep_list);

        /* disable dedicated endpoints */
        writel(0x0D, &dev->dep[0].dep_cfg);
        writel(0x0D, &dev->dep[1].dep_cfg);
        writel(0x0E, &dev->dep[2].dep_cfg);
        writel(0x0E, &dev->dep[3].dep_cfg);
        writel(0x0F, &dev->dep[4].dep_cfg);
        writel(0x0C, &dev->dep[5].dep_cfg);
}

static void usb_reinit(struct net2280 *dev)
{
        if (dev->quirks & PLX_LEGACY)
                return usb_reinit_228x(dev);
        return usb_reinit_338x(dev);
}

static void ep0_start_228x(struct net2280 *dev)
{
        writel(BIT(CLEAR_EP_HIDE_STATUS_PHASE) |
                BIT(CLEAR_NAK_OUT_PACKETS) |
                BIT(CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE),
                &dev->epregs[0].ep_rsp);

        /*
         * hardware optionally handles a bunch of standard requests
         * that the API hides from drivers anyway.  have it do so.
         * endpoint status/features are handled in software, to
         * help pass tests for some dubious behavior.
         */
        writel(BIT(SET_TEST_MODE) |
                BIT(SET_ADDRESS) |
                BIT(DEVICE_SET_CLEAR_DEVICE_REMOTE_WAKEUP) |
                BIT(GET_DEVICE_STATUS) |
                BIT(GET_INTERFACE_STATUS),
                &dev->usb->stdrsp);
        writel(BIT(USB_ROOT_PORT_WAKEUP_ENABLE) |
                BIT(SELF_POWERED_USB_DEVICE) |
                BIT(REMOTE_WAKEUP_SUPPORT) |
                (dev->softconnect << USB_DETECT_ENABLE) |
                BIT(SELF_POWERED_STATUS),
                &dev->usb->usbctl);

        /* enable irqs so we can see ep0 and general operation  */
        writel(BIT(SETUP_PACKET_INTERRUPT_ENABLE) |
                BIT(ENDPOINT_0_INTERRUPT_ENABLE),
                &dev->regs->pciirqenb0);
        writel(BIT(PCI_INTERRUPT_ENABLE) |
                BIT(PCI_MASTER_ABORT_RECEIVED_INTERRUPT_ENABLE) |
                BIT(PCI_TARGET_ABORT_RECEIVED_INTERRUPT_ENABLE) |
                BIT(PCI_RETRY_ABORT_INTERRUPT_ENABLE) |
                BIT(VBUS_INTERRUPT_ENABLE) |
                BIT(ROOT_PORT_RESET_INTERRUPT_ENABLE) |
                BIT(SUSPEND_REQUEST_CHANGE_INTERRUPT_ENABLE),
                &dev->regs->pciirqenb1);

        /* don't leave any writes posted */
        (void) readl(&dev->usb->usbctl);
}

static void ep0_start_338x(struct net2280 *dev)
{

        if (dev->bug7734_patched)
                writel(BIT(CLEAR_NAK_OUT_PACKETS_MODE) |
                       BIT(SET_EP_HIDE_STATUS_PHASE),
                       &dev->epregs[0].ep_rsp);

        /*
         * hardware optionally handles a bunch of standard requests
         * that the API hides from drivers anyway.  have it do so.
         * endpoint status/features are handled in software, to
         * help pass tests for some dubious behavior.
         */
        writel(BIT(SET_ISOCHRONOUS_DELAY) |
               BIT(SET_SEL) |
               BIT(SET_TEST_MODE) |
               BIT(SET_ADDRESS) |
               BIT(GET_INTERFACE_STATUS) |
               BIT(GET_DEVICE_STATUS),
                &dev->usb->stdrsp);
        dev->wakeup_enable = 1;
        writel(BIT(USB_ROOT_PORT_WAKEUP_ENABLE) |
               (dev->softconnect << USB_DETECT_ENABLE) |
               BIT(DEVICE_REMOTE_WAKEUP_ENABLE),
               &dev->usb->usbctl);

        /* enable irqs so we can see ep0 and general operation  */
        writel(BIT(SETUP_PACKET_INTERRUPT_ENABLE) |
               BIT(ENDPOINT_0_INTERRUPT_ENABLE),
               &dev->regs->pciirqenb0);
        writel(BIT(PCI_INTERRUPT_ENABLE) |
               BIT(ROOT_PORT_RESET_INTERRUPT_ENABLE) |
               BIT(SUSPEND_REQUEST_CHANGE_INTERRUPT_ENABLE) |
               BIT(VBUS_INTERRUPT_ENABLE),
               &dev->regs->pciirqenb1);

        /* don't leave any writes posted */
        (void)readl(&dev->usb->usbctl);
}

static void ep0_start(struct net2280 *dev)
{
        if (dev->quirks & PLX_LEGACY)
                return ep0_start_228x(dev);
        return ep0_start_338x(dev);
}

/* when a driver is successfully registered, it will receive
 * control requests including set_configuration(), which enables
 * non-control requests.  then usb traffic follows until a
 * disconnect is reported.  then a host may connect again, or
 * the driver might get unbound.
 */
static int net2280_start(struct usb_gadget *_gadget,
                struct usb_gadget_driver *driver)
{
        struct net2280          *dev;
        int                     retval;
        unsigned                i;

        /* insist on high speed support from the driver, since
         * (dev->usb->xcvrdiag & FORCE_FULL_SPEED_MODE)
         * "must not be used in normal operation"
         */
        if (!driver || driver->max_speed < USB_SPEED_HIGH ||
                        !driver->setup)
                return -EINVAL;

        dev = container_of(_gadget, struct net2280, gadget);

        for (i = 0; i < dev->n_ep; i++)
                dev->ep[i].irqs = 0;

        /* hook up the driver ... */
        driver->driver.bus = NULL;
        dev->driver = driver;

        retval = device_create_file(&dev->pdev->dev, &dev_attr_function);
        if (retval)
                goto err_unbind;
        retval = device_create_file(&dev->pdev->dev, &dev_attr_queues);
        if (retval)
                goto err_func;

        /* enable host detection and ep0; and we're ready
         * for set_configuration as well as eventual disconnect.
         */
        net2280_led_active(dev, 1);

        if ((dev->quirks & PLX_PCIE) && !dev->bug7734_patched)
                defect7374_enable_data_eps_zero(dev);

        ep0_start(dev);

        /* pci writes may still be posted */
        return 0;

err_func:
        device_remove_file(&dev->pdev->dev, &dev_attr_function);
err_unbind:
        dev->driver = NULL;
        return retval;
}

static void stop_activity(struct net2280 *dev, struct usb_gadget_driver *driver)
{
        int                     i;

        /* don't disconnect if it's not connected */
        if (dev->gadget.speed == USB_SPEED_UNKNOWN)
                driver = NULL;

        /* stop hardware; prevent new request submissions;
         * and kill any outstanding requests.
         */
        usb_reset(dev);
        for (i = 0; i < dev->n_ep; i++)
                nuke(&dev->ep[i]);

        /* report disconnect; the driver is already quiesced */
        if (driver) {
                spin_unlock(&dev->lock);
                driver->disconnect(&dev->gadget);
                spin_lock(&dev->lock);
        }

        usb_reinit(dev);
}

static int net2280_stop(struct usb_gadget *_gadget)
{
        struct net2280  *dev;
        unsigned long   flags;

        dev = container_of(_gadget, struct net2280, gadget);

        spin_lock_irqsave(&dev->lock, flags);
        stop_activity(dev, NULL);
        spin_unlock_irqrestore(&dev->lock, flags);

        net2280_led_active(dev, 0);

        device_remove_file(&dev->pdev->dev, &dev_attr_function);
        device_remove_file(&dev->pdev->dev, &dev_attr_queues);

        dev->driver = NULL;

        return 0;
}

/*-------------------------------------------------------------------------*/

/* handle ep0, ep-e, ep-f with 64 byte packets: packet per irq.
 * also works for dma-capable endpoints, in pio mode or just
 * to manually advance the queue after short OUT transfers.
 */
static void handle_ep_small(struct net2280_ep *ep)
{
        struct net2280_request  *req;
        u32                     t;
        /* 0 error, 1 mid-data, 2 done */
        int                     mode = 1;

        if (!list_empty(&ep->queue))
                req = list_entry(ep->queue.next,
                        struct net2280_request, queue);
        else
                req = NULL;

        /* ack all, and handle what we care about */
        t = readl(&ep->regs->ep_stat);
        ep->irqs++;

        ep_vdbg(ep->dev, "%s ack ep_stat %08x, req %p\n",
                        ep->ep.name, t, req ? &req->req : NULL);

        if (!ep->is_in || (ep->dev->quirks & PLX_2280))
                writel(t & ~BIT(NAK_OUT_PACKETS), &ep->regs->ep_stat);
        else
                /* Added for 2282 */
                writel(t, &ep->regs->ep_stat);

        /* for ep0, monitor token irqs to catch data stage length errors
         * and to synchronize on status.
         *
         * also, to defer reporting of protocol stalls ... here's where
         * data or status first appears, handling stalls here should never
         * cause trouble on the host side..
         *
         * control requests could be slightly faster without token synch for
         * status, but status can jam up that way.
         */
        if (unlikely(ep->num == 0)) {
                if (ep->is_in) {
                        /* status; stop NAKing */
                        if (t & BIT(DATA_OUT_PING_TOKEN_INTERRUPT)) {
                                if (ep->dev->protocol_stall) {
                                        ep->stopped = 1;
                                        set_halt(ep);
                                }
                                if (!req)
                                        allow_status(ep);
                                mode = 2;
                        /* reply to extra IN data tokens with a zlp */
                        } else if (t & BIT(DATA_IN_TOKEN_INTERRUPT)) {
                                if (ep->dev->protocol_stall) {
                                        ep->stopped = 1;
                                        set_halt(ep);
                                        mode = 2;
                                } else if (ep->responded &&
                                                !req && !ep->stopped)
                                        write_fifo(ep, NULL);
                        }
                } else {
                        /* status; stop NAKing */
                        if (t & BIT(DATA_IN_TOKEN_INTERRUPT)) {
                                if (ep->dev->protocol_stall) {
                                        ep->stopped = 1;
                                        set_halt(ep);
                                }
                                mode = 2;
                        /* an extra OUT token is an error */
                        } else if (((t & BIT(DATA_OUT_PING_TOKEN_INTERRUPT)) &&
                                        req &&
                                        req->req.actual == req->req.length) ||
                                        (ep->responded && !req)) {
                                ep->dev->protocol_stall = 1;
                                set_halt(ep);
                                ep->stopped = 1;
                                if (req)
                                        done(ep, req, -EOVERFLOW);
                                req = NULL;
                        }
                }
        }

        if (unlikely(!req))
                return;

        /* manual DMA queue advance after short OUT */
        if (likely(ep->dma)) {
                if (t & BIT(SHORT_PACKET_TRANSFERRED_INTERRUPT)) {
                        struct net2280_request *stuck_req = NULL;
                        int     stopped = ep->stopped;
                        int     num_completed;
                        int     stuck = 0;
                        u32     count;

                        /* TRANSFERRED works around OUT_DONE erratum 0112.
                         * we expect (N <= maxpacket) bytes; host wrote M.
                         * iff (M < N) we won't ever see a DMA interrupt.
                         */
                        ep->stopped = 1;
                        for (count = 0; ; t = readl(&ep->regs->ep_stat)) {

                                /* any preceding dma transfers must finish.
                                 * dma handles (M >= N), may empty the queue
                                 */
                                num_completed = scan_dma_completions(ep);
                                if (unlikely(list_empty(&ep->queue) ||
                                                ep->out_overflow)) {
                                        req = NULL;
                                        break;
                                }
                                req = list_entry(ep->queue.next,
                                        struct net2280_request, queue);

                                /* here either (M < N), a "real" short rx;
                                 * or (M == N) and the queue didn't empty
                                 */
                                if (likely(t & BIT(FIFO_EMPTY))) {
                                        count = readl(&ep->dma->dmacount);
                                        count &= DMA_BYTE_COUNT_MASK;
                                        if (readl(&ep->dma->dmadesc)
                                                        != req->td_dma)
                                                req = NULL;
                                        break;
                                }

                                /* Escape loop if no dma transfers completed
                                 * after few retries.
                                 */
                                if (num_completed == 0) {
                                        if (stuck_req == req &&
                                            readl(&ep->dma->dmadesc) !=
                                                  req->td_dma && stuck++ > 5) {
                                                count = readl(
                                                        &ep->dma->dmacount);
                                                count &= DMA_BYTE_COUNT_MASK;
                                                req = NULL;
                                                ep_dbg(ep->dev, "%s escape stuck %d, count %u\n",
                                                        ep->ep.name, stuck,
                                                        count);
                                                break;
                                        } else if (stuck_req != req) {
                                                stuck_req = req;
                                                stuck = 0;
                                        }
                                } else {
                                        stuck_req = NULL;
                                        stuck = 0;
                                }

                                udelay(1);
                        }

                        /* stop DMA, leave ep NAKing */
                        writel(BIT(DMA_ABORT), &ep->dma->dmastat);
                        spin_stop_dma(ep->dma);

                        if (likely(req)) {
                                req->td->dmacount = 0;
                                t = readl(&ep->regs->ep_avail);
                                dma_done(ep, req, count,
                                        (ep->out_overflow || t)
                                                ? -EOVERFLOW : 0);
                        }

                        /* also flush to prevent erratum 0106 trouble */
                        if (unlikely(ep->out_overflow ||
                                        (ep->dev->chiprev == 0x0100 &&
                                        ep->dev->gadget.speed
                                        == USB_SPEED_FULL))) {
                                out_flush(ep);
                                ep->out_overflow = 0;
                        }

                        /* (re)start dma if needed, stop NAKing */
                        ep->stopped = stopped;
                        if (!list_empty(&ep->queue))
                                restart_dma(ep);
                } else
                        ep_dbg(ep->dev, "%s dma ep_stat %08x ??\n",
                                        ep->ep.name, t);
                return;

        /* data packet(s) received (in the fifo, OUT) */
        } else if (t & BIT(DATA_PACKET_RECEIVED_INTERRUPT)) {
                if (read_fifo(ep, req) && ep->num != 0)
                        mode = 2;

        /* data packet(s) transmitted (IN) */
        } else if (t & BIT(DATA_PACKET_TRANSMITTED_INTERRUPT)) {
                unsigned        len;

                len = req->req.length - req->req.actual;
                if (len > ep->ep.maxpacket)
                        len = ep->ep.maxpacket;
                req->req.actual += len;

                /* if we wrote it all, we're usually done */
                /* send zlps until the status stage */
                if ((req->req.actual == req->req.length) &&
                        (!req->req.zero || len != ep->ep.maxpacket) && ep->num)
                                mode = 2;

        /* there was nothing to do ...  */
        } else if (mode == 1)
                return;

        /* done */
        if (mode == 2) {
                /* stream endpoints often resubmit/unlink in completion */
                done(ep, req, 0);

                /* maybe advance queue to next request */
                if (ep->num == 0) {
                        /* NOTE:  net2280 could let gadget driver start the
                         * status stage later. since not all controllers let
                         * them control that, the api doesn't (yet) allow it.
                         */
                        if (!ep->stopped)
                                allow_status(ep);
                        req = NULL;
                } else {
                        if (!list_empty(&ep->queue) && !ep->stopped)
                                req = list_entry(ep->queue.next,
                                        struct net2280_request, queue);
                        else
                                req = NULL;
                        if (req && !ep->is_in)
                                stop_out_naking(ep);
                }
        }

        /* is there a buffer for the next packet?
         * for best streaming performance, make sure there is one.
         */
        if (req && !ep->stopped) {

                /* load IN fifo with next packet (may be zlp) */
                if (t & BIT(DATA_PACKET_TRANSMITTED_INTERRUPT))
                        write_fifo(ep, &req->req);
        }
}

static struct net2280_ep *get_ep_by_addr(struct net2280 *dev, u16 wIndex)
{
        struct net2280_ep       *ep;

        if ((wIndex & USB_ENDPOINT_NUMBER_MASK) == 0)
                return &dev->ep[0];
        list_for_each_entry(ep, &dev->gadget.ep_list, ep.ep_list) {
                u8      bEndpointAddress;

                if (!ep->desc)
                        continue;
                bEndpointAddress = ep->desc->bEndpointAddress;
                if ((wIndex ^ bEndpointAddress) & USB_DIR_IN)
                        continue;
                if ((wIndex & 0x0f) == (bEndpointAddress & 0x0f))
                        return ep;
        }
        return NULL;
}

static void defect7374_workaround(struct net2280 *dev, struct usb_ctrlrequest r)
{
        u32 scratch, fsmvalue;
        u32 ack_wait_timeout, state;

        /* Workaround for Defect 7374 (U1/U2 erroneously rejected): */
        scratch = get_idx_reg(dev->regs, SCRATCH);
        fsmvalue = scratch & (0xf << DEFECT7374_FSM_FIELD);
        scratch &= ~(0xf << DEFECT7374_FSM_FIELD);

        if (!((fsmvalue == DEFECT7374_FSM_WAITING_FOR_CONTROL_READ) &&
                                (r.bRequestType & USB_DIR_IN)))
                return;

        /* This is the first Control Read for this connection: */
        if (!(readl(&dev->usb->usbstat) & BIT(SUPER_SPEED_MODE))) {
                /*
                 * Connection is NOT SS:
                 * - Connection must be FS or HS.
                 * - This FSM state should allow workaround software to
                 * run after the next USB connection.
                 */
                scratch |= DEFECT7374_FSM_NON_SS_CONTROL_READ;
                dev->bug7734_patched = 1;
                goto restore_data_eps;
        }

        /* Connection is SS: */
        for (ack_wait_timeout = 0;
                        ack_wait_timeout < DEFECT_7374_NUMBEROF_MAX_WAIT_LOOPS;
                        ack_wait_timeout++) {

                state = readl(&dev->plregs->pl_ep_status_1)
                        & (0xff << STATE);
                if ((state >= (ACK_GOOD_NORMAL << STATE)) &&
                        (state <= (ACK_GOOD_MORE_ACKS_TO_COME << STATE))) {
                        scratch |= DEFECT7374_FSM_SS_CONTROL_READ;
                        dev->bug7734_patched = 1;
                        break;
                }

                /*
                 * We have not yet received host's Data Phase ACK
                 * - Wait and try again.
                 */
                udelay(DEFECT_7374_PROCESSOR_WAIT_TIME);

                continue;
        }


        if (ack_wait_timeout >= DEFECT_7374_NUMBEROF_MAX_WAIT_LOOPS) {
                ep_err(dev, "FAIL: Defect 7374 workaround waited but failed "
                "to detect SS host's data phase ACK.");
                ep_err(dev, "PL_EP_STATUS_1(23:16):.Expected from 0x11 to 0x16"
                "got 0x%2.2x.\n", state >> STATE);
        } else {
                ep_warn(dev, "INFO: Defect 7374 workaround waited about\n"
                "%duSec for Control Read Data Phase ACK\n",
                        DEFECT_7374_PROCESSOR_WAIT_TIME * ack_wait_timeout);
        }

restore_data_eps:
        /*
         * Restore data EPs to their pre-workaround settings (disabled,
         * initialized, and other details).
         */
        defect7374_disable_data_eps(dev);

        set_idx_reg(dev->regs, SCRATCH, scratch);

        return;
}

static void ep_clear_seqnum(struct net2280_ep *ep)
{
        struct net2280 *dev = ep->dev;
        u32 val;
        static const u32 ep_pl[9] = { 0, 3, 4, 7, 8, 2, 5, 6, 9 };

        val = readl(&dev->plregs->pl_ep_ctrl) & ~0x1f;
        val |= ep_pl[ep->num];
        writel(val, &dev->plregs->pl_ep_ctrl);
        val |= BIT(SEQUENCE_NUMBER_RESET);
        writel(val, &dev->plregs->pl_ep_ctrl);

        return;
}

static void handle_stat0_irqs_superspeed(struct net2280 *dev,
                struct net2280_ep *ep, struct usb_ctrlrequest r)
{
        int tmp = 0;

#define w_value         le16_to_cpu(r.wValue)
#define w_index         le16_to_cpu(r.wIndex)
#define w_length        le16_to_cpu(r.wLength)

        switch (r.bRequest) {
                struct net2280_ep *e;
                u16 status;

        case USB_REQ_SET_CONFIGURATION:
                dev->addressed_state = !w_value;
                goto usb3_delegate;

        case USB_REQ_GET_STATUS:
                switch (r.bRequestType) {
                case (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE):
                        status = dev->wakeup_enable ? 0x02 : 0x00;
                        if (dev->gadget.is_selfpowered)
                                status |= BIT(0);
                        status |= (dev->u1_enable << 2 | dev->u2_enable << 3 |
                                                        dev->ltm_enable << 4);
                        writel(0, &dev->epregs[0].ep_irqenb);
                        set_fifo_bytecount(ep, sizeof(status));
                        writel((__force u32) status, &dev->epregs[0].ep_data);
                        allow_status_338x(ep);
                        break;

                case (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_ENDPOINT):
                        e = get_ep_by_addr(dev, w_index);
                        if (!e)
                                goto do_stall3;
                        status = readl(&e->regs->ep_rsp) &
                                                BIT(CLEAR_ENDPOINT_HALT);
                        writel(0, &dev->epregs[0].ep_irqenb);
                        set_fifo_bytecount(ep, sizeof(status));
                        writel((__force u32) status, &dev->epregs[0].ep_data);
                        allow_status_338x(ep);
                        break;

                default:
                        goto usb3_delegate;
                }
                break;

        case USB_REQ_CLEAR_FEATURE:
                switch (r.bRequestType) {
                case (USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE):
                        if (!dev->addressed_state) {
                                switch (w_value) {
                                case USB_DEVICE_U1_ENABLE:
                                        dev->u1_enable = 0;
                                        writel(readl(&dev->usb_ext->usbctl2) &
                                                ~BIT(U1_ENABLE),
                                                &dev->usb_ext->usbctl2);
                                        allow_status_338x(ep);
                                        goto next_endpoints3;

                                case USB_DEVICE_U2_ENABLE:
                                        dev->u2_enable = 0;
                                        writel(readl(&dev->usb_ext->usbctl2) &
                                                ~BIT(U2_ENABLE),
                                                &dev->usb_ext->usbctl2);
                                        allow_status_338x(ep);
                                        goto next_endpoints3;

                                case USB_DEVICE_LTM_ENABLE:
                                        dev->ltm_enable = 0;
                                        writel(readl(&dev->usb_ext->usbctl2) &
                                                ~BIT(LTM_ENABLE),
                                                &dev->usb_ext->usbctl2);
                                        allow_status_338x(ep);
                                        goto next_endpoints3;

                                default:
                                        break;
                                }
                        }
                        if (w_value == USB_DEVICE_REMOTE_WAKEUP) {
                                dev->wakeup_enable = 0;
                                writel(readl(&dev->usb->usbctl) &
                                        ~BIT(DEVICE_REMOTE_WAKEUP_ENABLE),
                                        &dev->usb->usbctl);
                                allow_status_338x(ep);
                                break;
                        }
                        goto usb3_delegate;

                case (USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_ENDPOINT):
                        e = get_ep_by_addr(dev, w_index);
                        if (!e)
                                goto do_stall3;
                        if (w_value != USB_ENDPOINT_HALT)
                                goto do_stall3;
                        ep_vdbg(dev, "%s clear halt\n", e->ep.name);
                        /*
                         * Workaround for SS SeqNum not cleared via
                         * Endpoint Halt (Clear) bit. select endpoint
                         */
                        ep_clear_seqnum(e);
                        clear_halt(e);
                        if (!list_empty(&e->queue) && e->td_dma)
                                restart_dma(e);
                        allow_status(ep);
                        ep->stopped = 1;
                        break;

                default:
                        goto usb3_delegate;
                }
                break;
        case USB_REQ_SET_FEATURE:
                switch (r.bRequestType) {
                case (USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE):
                        if (!dev->addressed_state) {
                                switch (w_value) {
                                case USB_DEVICE_U1_ENABLE:
                                        dev->u1_enable = 1;
                                        writel(readl(&dev->usb_ext->usbctl2) |
                                                BIT(U1_ENABLE),
                                                &dev->usb_ext->usbctl2);
                                        allow_status_338x(ep);
                                        goto next_endpoints3;

                                case USB_DEVICE_U2_ENABLE:
                                        dev->u2_enable = 1;
                                        writel(readl(&dev->usb_ext->usbctl2) |
                                                BIT(U2_ENABLE),
                                                &dev->usb_ext->usbctl2);
                                        allow_status_338x(ep);
                                        goto next_endpoints3;

                                case USB_DEVICE_LTM_ENABLE:
                                        dev->ltm_enable = 1;
                                        writel(readl(&dev->usb_ext->usbctl2) |
                                                BIT(LTM_ENABLE),
                                                &dev->usb_ext->usbctl2);
                                        allow_status_338x(ep);
                                        goto next_endpoints3;
                                default:
                                        break;
                                }
                        }